THE PLANTS OF MICHIGAN

PINACEAE, the Pine Family

Trees or shrubs, usually evergreen, with needle-like or scale-like leaves; fruit a cone or berry.

1a. Leaves in clusters of 2-5 — 2.

1b. Leaves mostly in clusters of 10 or more, on short lateral wart-like branches, deciduous each autumn Tamarack, Larix laricina.

1c. Leaves not in clusters — 4.

2a. Leaves in clusters of 5 White Pine, Pinus strobus.

2b. Leaves in clusters of 2 or 3 — 3.

3a. Leaves 8-15 cm. long Norway Pine, Pinus resinosa.

3b. Leaves 2-4 cm. long Jack Pine, Pinus banksiana.

4a. Leaves alternate or scattered — 5.

4b. Leaves opposite or whorled — 8.

5a. Leaves four-sided — 6.

5b. Leaves flattened — 7.

6a. Leaves 6-12 mm. long Black Spruce, Picea mariana.

6b. Leaves 15-25 mm. long White Spruce, Picea canadensis.

7a. Leaves short-stalked, 15 mm. long or less Hemlock, Tsuga canadensis.

7b. Leaves sessile, 15-30 mm. long Balsam, Abies balsamea.

8a. Leafy twigs soft and flattened White Cedar, Thuja occidentalis.

8b. Leafy twigs not distinctly flattened — 9.

9a. Leaves opposite — 10.

9b. Leaves in whorls of three — 11.

10a. Erect shrub or tree Red Cedar, Juniperus virginiana.

10b. Prostrate or spreading shrub Creeping Cedar, Juniperus horizontalis.

11a. Erect shrub or small tree Juniper, Juniperus communis.

11b. Spreading or ascending shrub, growing in dense mats Low Juniper, Juniperus communis var. depressa.

TAXACEAE, the Yew Family

Shrubs, with needle-like evergreen leaves; fruit red and berry-like.

One species in Michigan; straggling shrub 1-3 m. high Ground Hemlock, Taxus canadensis.

TYPHACEAE, the Cat-tail Family

Erect plants 1-2 m. high, with linear leaves and terminal spikes of brown flowers, appearing in summer.

1a. Staminate and pistillate portions of the flower-spike contiguous, the latter 2.5 cm. in diameter Common Cat-tail, Typha latifolia.

1b. Staminate and pistillate portions of the spike separated, the latter 2 cm. or less in diameter Narrow-leaved Cat-tail, Typha angustifolia.

SPARGANIACEAE, the Bur-reed Family

Marsh plants with linear leaves and spherical heads of inconspicuous greenish flowers, appearing in summer.

About 5 species occur in Michigan, of which the commonest is Bur-reed, Sparganium eurycarpum.

NAJADACEAE, the Pondweed Family

Aquatic plants with submerged or floating leaves and inconspicuous flowers in summer.

1a. Leaves opposite or whorled — 2.

1b. Leaves alternate — 2c.

2a. Leaves thread-like, 3-8 cm. long Horned Pondweed, Zannichellia palustris.

2b. Leaves linear, toothed, abruptly dilated at the base, 3 cm. long or less (Naiad) — 3.

2c. Leaves entire, not abruptly dilated at base [2]Pondweed, Potamogeton spp.

3a. Leaves about 2 mm. wide, sharply and coarsely toothed Naiad, Naias marina.

3b. Leaves very narrowly linear, with numerous minute teeth Naiad, Naias flexilis.

JUNCAGINACEAE, the Arrow Grass Family

Marsh plants, with linear cylindrical leaves and inconspicuous flowers in spikes or racemes, appearing in early summer.

1a. Leaves all basal; flowers numerous in a spike-like raceme (Arrow Grass) — 2.

1b. Stem-leaves present; flowers in a loose bracted raceme (1-3 dm. high). Scheuchzeria, Scheuchzeria palustris.

2a. Fruit (usually to be seen at the base of the raceme) ovoid or oblong, rounded at the base Arrow Grass, Triglochin maritima.

2b. Fruit linear, narrowed at the base (1-5 dm. high) Arrow Grass, Triglochin palustris.

ALISMACEAE, the Water Plantain Family

Marsh plants, with scape-like stems; flowers with 3 green sepals, 3 white petals, 6 or more stamens, and several separate pistils.

1a. Ovaries in a ring; flowers in panicles (2-8 dm. high, summer) Water Plantain, Alisma Plantago-aquatica.

1b. Ovaries in a head; flowers in racemes or umbels — 2.

2a. Flowers all perfect, in a single umbel of 2-8 flowers; stamens 9 (leaves lanceolate; 15 cm. high or less; summer) Dwarf Water Plantain, Echinodorus tenellus.

2b. Flowers in a raceme of 3-flowered whorls, the lower pistillate, the upper staminate; stamens usually more than nine (1-10 dm. high, summer) (Arrow-head) — 3.

3a. Leaves ovate to linear, not sagittate at base — 4.

3b. Leaves broad or narrow, sagittate at base — 5.

4a. Pistillate (basal) flowers sessile or nearly so (2-8 dm. high, summer) Arrow-head, Sagittaria heterophylla.

4b. Pistillate flowers with obvious pedicels Arrow-head, Sagittaria graminea.

5a. Basal lobes of the leaf conspicuous, triangular, almost or quite as long as the terminal portion — 6.

5b. Basal lobes small, short, linear — 4b.

6a. Beak of the achene very short and erect; rare species Arrow-head, Sagittaria arifolia.

6b. Beak of the achene sharp, incurved at right angles to the body; common species Arrow-head, Sagittaria latifolia.

HYDROCHARITACEAE, the Frog's Bit Family

Submerged aquatics, with inconspicuous flowers in summer.

1a. Leaves all from the base, 2 dm. long or more Eel Grass, Vallisneria spiralis.

1b. Leaves on the stem, 2 cm. long or less Water-weed, Elodea canadensis.

GRAMINEAE, the Grass Family

Grasses, with linear or narrow sheathing leaves, and very small flowers without perianth in the axils of chaffy bracts, appearing in late spring and summer.

Of the large number (over 150) of grasses in Michigan, only the commonest are included here, and the student is referred to the Manuals for a full treatment of them.

Their classification depends chiefly upon the structure and arrangement of the spikelets. These consist typically of a short axis, the rachilla, almost or quite concealed by several chaffy bracts. The two lower bracts are termed glumes, and have no flowers in their axils. Above the glumes are two or more other bracts, the lemmas. In the axil of each lemma, and usually concealed by it, is a smaller bract, the palea, and between the lemma and the palea is a single flower. The number of flowers in a spikelet is therefore normally equal to the number of lemmas. The spikelets are grouped in racemes, spikes, or panicles of various size.

1a. Spikelets one-flowered — 2.

1b. Spikelets with 2 or more flowers — 24.

2a. Spikelets grouped into dense solitary cylindrical spikes — 3.

2b. Spikelets arranged in panicles or in panicled spikes — 8.

3a. Spikelets without awns or bristles, or with short awns not more than 3 mm. long — 4.

3b. Spikelets with awns 2-5 cm. long, terminating the bracts Squirrel-tail, Hordeum jubatum.

3c. Bracts of the spikelet without terminal awns, but the spikelets with one or more long bristles arising from their base — 6.

4a. Spike-like panicle thickened in the middle, more than 1 cm. thick Beach Grass, Ammophila arenaria.

4b. Spike little or not at all thickened in the middle, less than 1 cm. thick — 5.

5a. Lower bracts awned; stem erect, unbranched Timothy, Phleum pratense.

5b. Lower scales unawned; stem branched at the base Floating Foxtail, Alopecurus geniculatus.

6a. Bristles 5 or more at the base of each spikelet Yellow Foxtail, Setaria glauca.

6b. Bristles 1-3 at the base of each spikelet — 7.

7a. Spikelets about 2 mm. long; bristles not much longer, green Green Foxtail, Setaria viridis.

7b. Spikelets about 3 mm. long; bristles much longer, usually purple Millet, Setaria italica.

8a. Spikelets numerous, in long slender symmetrical spikes — 9.

8b. Spikelets in panicles, racemes, or loose spikes — 13.

9a. Spikelets without awns; plants 8 dm. high or less (Crab Grass) — 10.

9b. Spikelets with awns; plants 12 dm. high or more — 12.

10a. Leaf-sheaths all glabrous. Crab Grass, Digitaria humifusa.

10b. Lower leaf-sheaths hairy — 11.

11a. Axis of the spike flat, with wing-like margins Crab Grass, Digitaria sanguinalis.

11b. Axis of the spike slender, without winged margins Crab Grass, Digitaria filiformis.

12a. Spikes numerous, appressed to the axis of the panicle; tall marsh grass Slough Grass, Spartina michauxiana.

12b. Spikes 2-6, widely divergent; plant of dry ground Blue-joint, Andropogon furcatus.

13a. Spikelets subtended by an ovoid thorny involucre 3-8 mm. wide Sand Bur, Cenchrus carolinianus.

13b. Spikelets without a thorny involucre — 14.

14a. Lower branches of the panicle spreading, bearing staminate flowers, the upper branches erect, with pistillate flowers; aquatic or marsh grass 2-4 m. high Wild Rice, Zizania aquatica.

14b. Panicle uniform throughout — 15.

15a. Spikelets with awns 2 mm. or more long — 16.

15b. Spikelets not awned, or with short inconspicuous awns — 18.

16a. Spikelets in solitary raceme-like spikes; awn about 1 cm. long or more Beard Grass, Andropogon scoparius.

16b. Spikelets in branching clusters; awn less than 1 cm. long — 17.

17a. Leaf-blade 4 mm. wide or narrower; panicle slender Drop-seed, Muhlenbergia schreberi.

17b. Leaf-blade 6 mm. wide or more; panicle stout and coarse Barnyard Grass, Echinochloa crus-galli.

18a. Spikelet plump and compact, its bracts closely folded about each other — 19.

18b. Spikelet very flat, its two bracts closely folded together Cut-grass, Leersia oryzoides.

18c. Spikelet loose and open, somewhat flattened, its 3 bracts ascending or spreading and not closely folded about each other — 20.

19a. Panicle about half as long as the entire plant; leaves copiously hairy Witch Grass, Panicum capillare.

19b. Panicle of smaller size Panic-grasses, various species of Panicum.

20a. Panicle strongly contracted or spike-like; plants of sand-dunes — 4a.

20b. Panicle spreading or slightly contracted; axis of the spikelet beset with bristles; leaves 2 dm. long or more; marsh grass Reed Grass, Calamagrostis canadensis.

20c. Panicle spreading or somewhat contracted, but not spike-like; axis of the spikelet without bristles — 21.

21a. Panicle-branches erect or ascending — 22.

21b. Panicle-branches strongly spreading — 23.

22a. The two outer scales of the spikelet one-fourth as long as the third scale, or sometimes one of them absent — 17a.

22b. The glumes at least half as long as the lemma Wood-grass, Muhlenbergia mexicana.

23a. The chief lateral branches of the panicle dividing and bearing flowers below their middle Red-top, Agrostis alba.

23b. The chief branches of the panicle dividing only beyond the middle Hair Grass, Agrostis hyemalis.

24a. Spikelets arranged in two rows to form a definite spike — 25.

24b. Spikelets in panicles, never in definite rows — 29.

25a. Spikelets in a single row on one side of the axis, forming a one-sided spike Yard Grass, Eleusine indica.

25b. Spikelets alternating on opposite sides of the axis, forming a two-rowed spike — 26.

26a. Spikelets in pairs at each joint, forming a dense spike (Wild Rye) — 27.

26b. Spikelets single at each joint, forming a loose, open or interrupted spike — 28.

27a. Glumes lanceolate Wild Rye, Elymus canadensis.

27b. Glumes narrowly subulate Wild Rye, Elymus virginicus.

28a. Spikelets with their edges toward the axis of the spike Rye Grass, Lolium perenne.

28b. Spikelets with their sides toward the axis of the spike Quack Grass, Agropyron repens.

29a. Glumes longer than the lemmas Oats, Avena sativa.

29b. Glumes shorter than the lemmas — 30.

30a. Axis of the spikelet beset with conspicuous long hairs about equaling the lemmas; tall marsh grass 1-4 m. high Reed, Phragmites communis.

30b. Spikelets without conspicuous long hairs — 31.

31a. Spikelets sessile or nearly so, forming crowded or spike-like panicles — 32.

31b. Spikelets distinctly panicled — 33.

32a. Spikelets in dense one-sided clusters at the ends of the panicle branches Orchard Grass, Dactylis glomerata.

32b. Spikelets in an erect spike-like cluster Prairie June-grass, Koeleria cristata.

33a. Lemmas, exclusive of the awn when present, 8 mm. long or more — 34.

33b. Lemmas, exclusive of the awn when present, 6 mm. long or less — 35.

34a. Awns on the lemmas 12 mm. long or more Brome-grass, Bromus tectorum.

34b. Awns on the lemmas 8 mm. long or less, or none Cheat, Bromus secalinus.

35a. Lemmas with 7 sharp conspicuous veins from base to apex Manna Grass, Glyceria nervata.

35b. Lemmas with 3-5 inconspicuous veins — 36.

36a. Spikelets with 5 flowers or more — 37.

36b. Spikelets with 2-4 (rarely 5) flowers — 40.

37a. Stems tufted and decumbent at base (Love Grass) — 38.

37b. Stems erect (Fescue Grass) — 39.

38a. Spikelets 1.5 mm. wide Love Grass, Eragrostis pilosa.

38b. Spikelets 3 mm. wide Love Grass, Eragrostis megastachya.

39a. Lemmas with conspicuous awns Fescue Grass, Festuca octoflora.

39b. Lemmas without awns Fescue Grass, Festuca elatior.

40a. Tufted annual grass Spear Grass, Poa annua.

40b. Perennials, with erect flowering stems — 41.

41a. Stems round Blue Grass, Poa pratensis.

41b. Stems strongly flattened Canadian Blue Grass, Poa compressa.

CYPERACEAE, the Sedge Family

Grass-like or rush-like plants, with linear leaves or leafless, and inconspicuous flowers in small chaffy spikes.

Over 200 species occur in Michigan, of which only the commonest are included here. For the remaining species the Manuals should be consulted.

1a. Spikes all alike — 2.

1b. The uppermost spike or spikes wholly staminate, the lower one or more pistillate; ovary and achene surrounded by a sac, the perigynium. Mature fruit is necessary for satisfactory identification (Sedge) — 12.

2a. Stems leafless, bearing one or more spikes at or near the top — 3.

2b. Stems leafy — 6.

3a. Spike one, terminal and erect (Spike Rush) — 4.

3b. Spikes usually more than one, lateral and spreading — 5.

4a. Annual, with fibrous roots Spike Rush, Eleocharis obtusa.

4b. Perennial, with a running rootstock Spike Rush, Eleocharis palustris.

5a. Stem round Bulrush, Scirpus validus.

5b. Stem 3-cornered Three-square, Scirpus americanus.

6a. Spikes axillary along the side of the stem Dulichium, Dulichium, arundinaceum.

6b. Spikes terminal — 7.

7a. Spikes subtended by long conspicuous leaves which greatly exceed the flower clusters — 8.

7b. Spikes not conspicuously exceeded by the bract-like leaves — 10.

8a. Spikes in a dense head-like cluster, white-woolly at maturity Cotton Grass, Eriophorum virginicum.

8b. Spikes not in dense heads, nor white-woolly at maturity — 9.

9a. Perennial by a creeping rootstock Nut Grass, Cyperus esculentus.

9b. Perennial by hard basal corms Cyperus, Cyperus strigosus.

10a. Bracts of the spike chestnut-brown Twig Rush, Cladium mariscoides.

10b. Bracts of the spike green or straw-color (Sedge) — 11.

11a. Spikes 3-8, separate Sedge, Carex straminea.

11b. Spikes very numerous and densely crowded Sedge, Carex vulpinoidea.

12a. Achenes flattened Sedge, Carex crinita.

12b. Achenes 3-angled — 13.

13a. Perigynium tipped with a sharp straight 2-toothed beak — 14.

13b. Perigynium with a short soft beak — 17.

14a. Perigynium thin and papery, loosely enclosing the achene — 15.

14b. Perigynium firm, closely enclosing the achene — 16.

15a. Perigynium less than 1 cm. long Sedge, Carex hystericina.

15b. Perigynium more than 1 cm. long Sedge, Carex lupulina.

16a. Perigynium smooth Sedge, Carex riparia.

16b. Perigynium hairy Sedge, Carex filiformis.

17a. Beak of the perigynium bent abruptly to one side Sedge, Carex laxiflora.

17b. Beak of the perigynium straight Sedge, Carex pennsylvanica.

ARACEAE, the Arum Family

Individual flowers small, but crowded on a fleshy spadix to form a conspicuous spike, usually surrounded by a green or colored spathe.

1a. Leaves compound — 2.

1b. Leaves simple — 3.

2a. Leaflets 3, spathe pale green or purple (3-6 dm. high; spring) Indian Turnip, Arisaema triphyllum.

2b. Leaflets 7-11; spathe green; spadix long and slender (3-8 dm. high; late spring) Dragon Root, Arisaema dracontium.

3a. Leaves linear, sword-shape; spathe none (5-15 dm. high; early summer) Sweet Flag, Acorus calamus.

3b. Leaves broader than linear; spathe present — 4.

4a. Flower clusters partly underground, appearing in earliest spring Skunk Cabbage, Symplocarpus foetidus.

4b. Flower clusters peduncled, in early summer — 5.

5a. Leaves broadly ovate-cordate; spathe white Water Arum, Calla palustris.

5b. Leaves more or less sagittate; spathe green Arrow Arum, Peltandra virginica.

LEMNACEAE, the Duckweed Family

Minute leafless plants floating on quiet water; flowers exceedingly small and seldom seen.

1a. Plant thick, ovoid, less than 2 mm. long; roots none. Two species are reported from Michigan Wolffia spp.

1b. Plant flattened, with short roots — 2.

2a. Roots several from each rounded plant Duckweed, Spirodela polyrhiza.

2b. Root single from each rounded plant Duckweed, Lemna spp.

Three species are reported from Michigan, of which the commonest is Lemna minor.

ERIOCAULACEAE, the Pipewort Family

Bog or marsh herbs, with small flowers in heads terminating long slender scapes.

One species in Michigan; leaves linear and basal; flower-stalk 5-15 cm. high; flower-heads whitish or lead-color Pipewort, Eriocaulon articulatum.

XYRIDACEAE, the Yellow-eyed Grass Famil

Small herbs with basal leaves and erect flower-stalks bearing a head of perfect yellow flowers, in summer.

1a. Base of plant bulbous-thickened (3-6 dm. high) Yellow-eyed Grass, Xyris flexuosa.

1b. Base of plant not bulbous-thickened (1-3 dm. high) Yellow-eyed Grass, Xyris montana.

COMMELINACEAE, the Spiderwort Family

Leafy-stemmed herbs; flowers with 3 sepals, 3 petals, and 6 stamens, lasting but a single day; petals blue.

1a. Stamens 6; petals all equal (Spiderwort) — 2.

1b. Perfect stamens 3, sterile stamens 3; two of the petals larger than the third (3-6 dm. high; summer) Day-flower, Commelina virginica.

2a. Sepals villous (3-10 dm. high; late spring) Spiderwort, Tradescantia virginiana.

2b. Sepals glabrous, or with a tuft of hairs at the apex (4-10 dm. high; late spring) Spiderwort, Tradescantia reflexa.

PONTEDERIACEAE, the Pickerel-weed Family

Aquatic herbs, with 6 rather conspicuous petals; flowers in summer.

1a. Flowers blue; leaves cordate-sagittate (3-10 dm. high) Pickerel-weed, Pontederia cordata.

1b. Flowers yellow; leaves linear (submerged) Mud Plantain, Heteranthera dubia.

JUNCACEAE, the Rush Family

Grass-like or rush-like plants, with inconspicuous greenish or brownish flowers, of 3 chaffy or scale-like sepals and as many similar petals.

1a. Leaf-sheaths closed; capsule 1-celled and 3-seeded; stem or leaves usually hairy at or near the base (1-4 dm. high). (Wood Rush) — 2.

1b. Leaf-sheaths open; capsule many-seeded; plants never hairy — 4.

2a. Flowers solitary at the ends of the branches of the umbel-like cluster (spring) Wood Rush, Luzula saltuensis.

2b. Flowers in spikes or dense clusters — 3.

3a. Flower-cluster spike-like, nodding at the tip (summer) Wood Rush, Luzula spicata.

3b. Flower-cluster umbel-like (spring) Wood Rush, Luzula campestris var. multiflora.

4. The genus Juncus, or Rush, contains about 25 species in Michigan, blooming in summer or autumn. For their identification the Manuals should be consulted. One of the commonest species is Juncus effusus, growing in marshes, with erect leafless cylindrical stems, bearing a lateral cluster of flowers near the summit. Another common species is Juncus tenuis, with slender stems and linear leaves, growing in hard ground, especially in woodland paths.

LILIACEAE, the Lily Family

Herbs or twining shrubs, with generally conspicuous flowers; sepals and petals each 3, and usually colored alike, stamens 6, ovary 3-celled, superior. In one species the perianth is 4-parted and the stamens are 4.

1a. Flowers or flower-clusters lateral, axillary or apparently so — 2.

1b. Flowers or flower-clusters scapose or terminal — 12.

2a. Leaves minute and scale-like (7-15 dm. high; flowers greenish-yellow, June) Asparagus, Asparagus officinalis.

2b. Leaves broad and flat, not scale-like — 3.

3a. Flowers numerous in rounded umbels; perianth-segments nearly separate; leaves long-petioled — 4.

3b. Flowers in clusters of 1-8; leaves short-petioled, sessile, or clasping — 8.

4a. Stems herbaceous (flowers greenish-yellow, ill-scented) (Carrion-flower) — 5.

4b. Stems woody, thorny, climbing (flowers greenish-yellow, early summer) (Green Brier) — 7.

5a. Stems climbing by tendrils — 6.

5b. Stem not climbing; only the upper leaves, or none, with tendrils Carrion-flower, Smilax ecirrhata.

6a. Leaves smooth beneath. Carrion-flower, Smilax herbacea.

6b. Leaves minutely pubescent beneath when mature Carrion-flower, Smilax herbacea var. pulverulenta.

7a. Leaves with 5 principal veins. Green Brier, Smilax rotundifolia.

7b. Leaves with 7 principal veins. Green Brier, Smilax hispida.

8a. Perianth-segments united into a tube (flowers axillary, late spring) (Solomon's Seal) — 9.

8b. Perianth-segments separate (2-8 dm. high; spring) (Twisted-stalk) — 10.

9a. Leaves minutely pubescent beneath; filaments rough, inserted at three-fourths the length of the perianth (3-8 dm. high) Small Solomon's Seal, Polygonatum biflorum.

9b. Leaves smooth beneath; filaments smooth, inserted at the middle of the perianth tube (5-15 dm. high) Great Solomon's Seal, Polygonatum commutatum.

10a. Leaves distinctly clasping the stem; flowers greenish-white Twisted-stalk, Streptopus amplexifolius.

10b. Leaves closely sessile; flowers reddish to purple — 11.

11a. Rootstock short and thick; berries spherical Twisted-stalk, Streptopus roseus.

11b. Rootstock long and slender; berries 3-angled Twisted-stalk, Streptopus longipes.

12a. Perianth-segments 5-12 cm. long — 13.

12b. Perianth-segments shorter than 5 cm. — 19.

13a. Leaves all or chiefly basal, stem-leaves bract-like or none — 14.

13b. Leaves chiefly or entirely on the stem — 15.

14a. Leaves numerous, linear or sword-shape (flowers orange, summer) Day Lily, Hemerocallis fulva.

14b. Leaves a single pair, oblong or lanceolate — 21.

15a. Leaves a single whorl of 3 (Wake Robin, Trillium) — 22.

15b. Leaves numerous (6-12 dm. high; flowers yellow, orange, or red, in summer) (Lily) — 16.

16a. Flowers erect — 17.

16b. Flowers nodding — 18.

17a. Leaves narrowly lanceolate, 6-15 mm. wide, mostly whorled Wood Lily, Lilium philadelphicum.

17b. Leaves linear, 5 mm. wide or less, almost all alternate Wood Lily, Lilium philadelphicum var. andinum.

18a. Perianth-segments strongly revolute Turk's-cap Lily, Lilium superbum.

18b. Perianth-segments half-recurved Yellow Lily, Lilium canadense.

19a. Flower solitary — 20.

19b. Flowers in clusters, not solitary — 31.

20a. Stem with a single pair of basal leaves (Dog's-tooth Violet) — 21.

20b. Stem with a single whorl of 3 leaves (1-3 dm. high; spring) (Wake Robin, Trillium) — 22.

20c. Stem leafy (Bellwort) — 29.

21a. Perianth yellow Dog's-tooth Violet, Erythronium americanum.

21b. Perianth white, bluish, or pinkish Dog's-tooth Violet, Erythronium albidum.

22a. Flower sessile, red or brown — 23.

22b. Flower peduncled, white or pink, rarely red — 24.

23a. Leaves sessile, sepals spreading Wake Robin, Trillium sessile.

23b. Leaves short-petioled, sepals reflexed Wake Robin, Trillium recurvatum.

24a. Ovary with 6 distinct wing-like angles — 25.

24b. Ovary obtusely 3-angled or lobed — 28.

25a. Stamens distinctly longer than the pistil — 26.

25b. Stamens equaling or shorter than the pistil — 27.

26a. Stigmas erect or nearly so, slender Wake Robin, Trillium grandiflorum.

26b. Stigmas strongly recurved or spreading Wake Robin, Trillium erectum.

27a. Filaments about as long as the anthers Wake Robin, Trillium cernuum.

27b. Filaments half as long as the anthers or shorter Wake Robin, Trillium declinatum.

28a. Leaves obtuse; petals obtuse, white Dwarf White Trillium, Trillium nivale.

28b. Leaves acuminate; petals acute, purple-striped at base Painted Trillium, Trillium undulatum.

29a. Leaves sessile (3-6 dm. high; flowers yellow, spring) Bellwort, Oakesia sessilifolia.

29b. Leaves perfoliate (4-6 dm. high; flowers yellow, in spring) — 30.

30a. Leaves minutely pubescent beneath Bellwort, Uvularia grandiflora.

30b. Leaves glabrous and all glaucous Bellwort, Uvularia perfoliata.

31a. Stem bearing 2 whorls of 3-9 leaves (3-6 dm. high; flowers pale yellow, early summer) Indian Cucumber-root, Medeola virginiana.

31b. Stem-leaves not whorled, or all leaves basal — 32.

32a. Flowers in umbels — 33.

32b. Flowers in racemes or panicles — 38.

33a. Plant with the odor of onions or garlic (leaves all or chiefly basal; flower-stalks 2-8 dm. high, late spring or summer) — 34.

33b. Plant not with the odor of onions (leaves basal; flower-stalks 2-3 dm. high, with an umbel of 3-6 greenish-yellow flowers in late spring) Clintonia, Clintonia borealis.

34a. Leaves oblong, 2-5 cm. wide, not present when the plants are in bloom (greenish-white flowers) Wild Leek, Allium tricoccum.

34b. Leaves linear, present with the flowers — 35.

35a. Umbel nodding or horizontal (petals rose-color) Wild Onion, Allium cernuum.

35b. Umbel erect — 36.

36a. Pedicels longer than the flowers — 37.

36b. Pedicels equaling or shorter than the flowers (petals rose-purple) Wild Chives, Allium schoenoprasum var. sibiricum.

37a. Leaves flattened; flowers pink to white Wild Onion, Allium canadense.

37b. Leaves cylindrical; flowers greenish to purple Field Garlic, Allium vineale.

38a. Leaves lanceolate to ovate, not more than 8 times as long as broad — 39.

38b. Leaves linear or grass-like, at least 12 times as long as broad — 45.

39a. Principal leaves all basal, stem-leaves none or bract-like — 40.

39b. Principal leaves on the stem — 41.

40a. Flowers in a spike-like raceme (4-10 dm. high; small white flowers in summer) Colic-root, Aletris farinosa.

40b. Flowers in an umbel-like cluster — 34b.

41a. Perianth-segments 4 (1-2 dm. high; flowers white, early summer) Wild Lily of the Valley, Maianthemum canadense.

41b. Perianth-segments 6 — 42.

42a. Styles 3; flowers dioecious (3-10 dm. high; flowers white, early summer) Blazing Star, Chamaelirium luteum.

42b. Style 1; flowers perfect, white, in spring (False Solomon's Seal) — 43.

43a. Flowers panicled (3-6 dm. high) False Solomon's Seal, Smilacina racemosa.

43b. Flowers racemed — 44.

44a. Leaves 2-4, usually 3 (1-2 dm. high) False Solomon's Seal, Smilacina trifolia.

44b. Leaves 5-12 (2-5 dm. high) False Solomon's Seal, Smilacina stellata.

45a. Flowers bright blue; perianth-segments united (2-3 dm. high, spring) Grape Hyacinth, Muscari botryoides.

45b. Flowers blue, greenish, yellowish, or white; perianth-segments separate — 46.

46a. Flowers 1 cm. wide, or smaller (white or greenish, in racemes, late spring or summer) (False Asphodel) — 47.

46b. Flowers 1.5 cm. wide, or larger — 48.

47a. Stem glabrous (2 dm. high or less) False Asphodel, Tofieldia palustris.

47b. Stem viscid-pubescent (1-5 dm. high) False Asphodel, Tofieldia glutinosa.

48a. Perianth-segments with 2 glands near the base (3-8 dm. high; greenish-white panicled flowers in summer) Zygadenus, Zygadenus chloranthus.

48b. Perianth-segments without glands — 49.

49a. Plant 3-5 dm. tall; flowers blue or nearly white, in long racemes (early summer) Wild Hyacinth, Camassia esculenta.

49b. Plant 1-3 dm. tall; flowers greenish-white, in short corymb-like racemes (spring) Star of Bethlehem, Ornithogalum umbellatum.

DIOSCOREACEAE, the Yam Family

Twining herbs with net-veined leaves and greenish or white flowers in panicles or racemes.

One species in Michigan; leaves ovate-cordate; flowers in summer Wild Yam, Dioscorea villosa.

AMARYLLIDACEAE, the Amaryllis Family

Plants with linear basal leaves, and perfect flowers, with 6-parted perianth, inferior ovary, and 6 stamens.

One species in Michigan; 1-2 dm. high; flowers yellow, 1 cm. wide, in spring Star Grass, Hypoxis hirsuta.

IRIDACEAE, the Iris Family

Herbs, with 6-parted perianth, inferior ovary, and 3 stamens.

1a. Flowers blue, 5 cm. wide or larger — 2.

1b. Flowers about 1 cm. wide (blue or white, from a spathe terminating a 2-edged stem 2-5 dm. high, spring and early summer) (Blue-eyed Grass) — 3.

2a. Flowering stems 4-8 dm. high (early summer) Blue Flag, Iris versicolor.

2b. Flowering stems 2 dm. or less high (spring) Dwarf Iris, Iris lacustris.

3a. Spathes terminal, sessile — 4.

3b. Spathes long-peduncled, axillary — 8.

4a. Spathe single — 5.

4b. Spathes 2 on each flowering stem — 7.

5a. Pedicels much longer than the inner (shorter) bract Blue-eyed Grass, Sisyrinchium mucronatum.

5b. Pedicels equaling or barely exceeding the inner bract — 6.

6a. Capsule brown; common species Blue-eyed Grass, Sisyrinchium angustifolium.

6b. Capsule green or yellowish; rare species Blue-eyed Grass, Sisyrinchium montanum.

7a. Leaves folded lengthwise; stems narrowly winged Blue-eyed Grass, Sisyrinchium hastile.

7b. Leaves flat; stem broadly winged, 2-3 mm. wide Blue-eyed Grass, Sisyrinchium albidum.

8a. Capsules pale straw-color or whitish — 9.

8b. Capsules brown, or tinged with purple — 10.

9a. Plant with straight fibrous bristles at base; pedicels long-exserted Blue-eyed Grass, Sisyrinchium farwellii.

9b. Plants not bristly at base; pedicels barely exserted Blue-eyed Grass, Sisyrinchium strictum.

10a. Pedicels scarcely exceeding the inner bract — 6a.

10b. Pedicels much exceeding the inner bract — 11.

11a. Stem 2-6 mm. wide; bracts 1.5-2 cm. long Blue-eyed Grass, Sisyrinchium gramineum.

11b. Stem 1-2 mm. wide; bracts 1-1.5 cm. long Blue-eyed Grass, Sisyrinchium apiculatum.

ORCHIDACEAE, the Orchis Family

Herbs, with irregular flowers, one petal, the lip, differing from the others in size and shape, inferior ovary, and one or two stamens adherent to the style.

1a. Flowers in a spike-like obviously twisted raceme; small, yellowish or greenish-white, in late summer and autumn (except 4a) (Ladies' Tresses) — 2.

1b. Flowers solitary or in clusters, but never in a twisted raceme — 5.

2a. Flowers in 1 row Ladies' Tresses, Spiranthes gracilis.

2b. Flowers in several rows — 3.

3a. Lip constricted near the apex Ladies' Tresses, Spiranthes romanzoftiana.

3b. Lip not constricted — 4.

4a. Lip yellow; flowers in spring and early summer Ladies' Tresses, Spiranthes lucida.

4b. Lip white Ladies' Tresses, Spiranthes cernua.

5a. Brown, purple, or yellow plants, without green color, with scale-like leaves (1-4 dm. high; summer) (Coral Root) — 6.

5b. Plants with normal green color — 9.

6a. Lip white, not spotted Coral Root, Corallorrhiza trifida.

6b. Lip white, spotted with red — 7.

7a. Lip distinctly 3-lobed Coral Root, Corallorrhiza maculata.

7b. Lip entire, or barely toothed — 8.

8a. Flower, exclusive of ovary, 4 mm. long Coral Root, Corallorrhiza odontorhiza.

8b. Flower about 10 mm. long. Coral Root, Corallorrhiza striata.

9a. Leaf 1 or none at flowering time — 10.

9b. Leaves a single pair, basal, or opposite on the stem; never alternate on the stem — 19.

9c. Leaves several, all basal, prominently net-veined, and frequently blotched with white (scape 1-4 dm. high; flowers whitish, pubescent, in summer) (Rattlesnake Plantain) — 26.

9d. Leaves 2 or more, on the stem — 28.

10a. Foliage leaf absent or undeveloped at flowering time, or merely persisting through the winter from the previous year — 11.

10b. Foliage leaf present at flowering time — 12.

11a. Flower rose-purple, 3-5 cm. long, solitary or two (1-3 dm. high, early summer) Arethusa, Arethusa bulbosa.

11b. Flowers purplish-green, in racemes, with a spur 2 cm. long Crane-fly Orchis, Tipularia discolor.

11c. Flowers yellowish, purple tinged, in racemes; spur none (3-4 dm. high, early summer). Putty Root, Aplectrum hyemale.

12a. Leaf linear or linear-lanceolate — 13.

12b. Leaf of a broader shape — 14.

13a. Flower solitary or two; leaf just below the flower — 11a.

13b. Flowers in a loose raceme, sometimes only 2; leaf basal Calopogon, Calopogon pulchellus.

14a. Flowers greenish, yellowish, or white — 15.

14b. Flowers pink to purple, often variegated — 17.

15a. Flowers 6-10 mm. wide, with a spur about the same length (1-4 dm. high, summer) (Rein Orchis) — 35.

15b. Flowers 5 mm. wide or less; spur none (1-2 dm. high; summer) (Adder's Mouth) — 16.

16a. Pedicels less than 5 mm. long; lip broadest below the middle Adder's Mouth, Microstylis monophyllos.

16b. Pedicels more than 5 mm. long; lip broadest near the apex Adder's Mouth, Microstylis unifolia.

17a. Flowers spicate; lip distinctly 3-lobed (1-2 dm. high; early summer) — 24.

17b. Flowers solitary or two — 18.

18a. Leaf on the stem, lanceolate to ovate — 34a.

18b. Leaf basal, round-ovate (2 dm. high or less; early summer) Calypso, Calypso bulbosa.

19a. Leaves opposite and sessile near the middle of the stem (1-3 dm. high; flowers in summer) (Tway-blade) — 20.

19b. Leaves basal — 21.

20a. Lip deeply 2-cleft (flowers purplish) Tway-blade, Listera cordata.

20b. Lip wedge-shape, with 2 round shallow lobes (flowers greenish-yellow) Tway-blade, Listera convallarioides.

21a. Lip an inflated sac about 4 cm. long — 29d.

21b. Lip not sac-like — 22.

22a. Flower with a spur 15-50 mm. long — 23.

22b. Flower not spurred (1-2 dm. high; early summer) (Tway-blade) — 25.

23a. Flowers purple or magenta, or with white markings — 24.

23b. Flowers greenish, yellowish, or white (1-4 dm. high; summer) (Rein Orchis) — 36.

24a. Leaf 1 (1-2 dm. high; early summer) Round-leaved Orchis, Orchis rotundifolia.

24b. Leaves 2 (-20 cm. high; late spring) Showy Orchis, Orchis spectabilis.

25a. Lip about 10 mm. long, purple Tway-blade, Liparis liliifolia.

25b. Lip about 5 mm. long, yellowish-green Tway-blade, Liparis loeselii.

26a. Perianth 8-10 mm. long; lip with elongated point Rattlesnake Plantain, Epipactis decipiens.

26b. Perianth 4-6 mm. long; lip sack-like — 27.

27a. Raceme loosely flowered, one-sided Rattlesnake Plantain, Epipactis repens var. ophioides.

27b. Raceme closely flowered, not one-sided Rattlesnake Plantain, Epipactis pubescens.

28a. Lip conspicuously sack-like, inflated (late spring and early summer) (Lady's Slipper) — 29.

28b. Lip not sack-like nor inflated — 32.

29a. Lip white (1-3 dm. high) White Lady's Slipper, Cypripedium candidum.

29b. Lip yellow (2-7 dm. high) — 30.

29c. Lip white, with crimson or purple markings — 31.

29d. Lip pink (1-4 dm. high, late spring) Stemless Lady's Slipper, Cypripedium acaule.

30a. Lip 2-3 cm. long. Small Yellow Lady's Slipper, Cypripedium parviflorum.

30b. Lip 3.5-5 cm. long Large Yellow Lady's Slipper, Cypripedium parviflorum var. pubescens.

31a. Lip 2 cm. long or less; sepals separate (1.5-3 dm. high) Ram's Head Lady's Slipper, Cypripedium arietinum.

31b. Lip 3 cm. long or more; the 2 lower sepals united Showy Lady's Slipper, Cypripedium hirsutum.

32a. Flowers solitary in the axils, or solitary and terminal; not spurred — 33.

32b. Flowers in terminal racemes, spurred — 38.

33a. Leaves a whorl of 5 (2-3 dm. high; petals greenish; late summer) Whorled Pogonia, Pogonia verticillata.

33b. Leaves alternate — 34.

34a. Leaves lanceolate or narrowly ovate, 2-8 cm. long, narrowed at base; flower terminal (1-4 dm. high; flowers pink purple, early summer) Snake Mouth, Pogonia ophioglossoides.

34b. Leaves ovate, 1-2 cm. long, clasping; flowers axillary (5-20 cm. high; flowers purple, summer) Nodding Pogonia, Pogonia trianthophora.

35a. Leaf basal; spur nearly straight Rein Orchis, Habenaria obtusata.

35b. Leaf on the stem; spur strongly curved Rein Orchis, Habenaria clavellata.

36a. Flower-stalk without bracts below the raceme; flowers yellowish-green Rein Orchis, Habenaria hookeri.

36b. Flower-stalk bearing bracts below the raceme; flowers greenish-white — 37.

37a. Spur 15-25 mm. long Rein Orchis, Habenaria orbiculata.

37b. Spur 30-50 mm. long Rein Orchis, Habenaria macrophylla.

38a. Lip fringed (Fringed Orchis) — 43.

38b. Lip not fringed (Rein Orchis) — 39.

39a. Lip with 2-3 evident teeth at apex — 40.

39b. Lip without apical teeth — 41.

40a. Stem-leaves 3 or more Rein Orchis, Habenaria bracteata.

40b. Stem-leaves 2 — 35b.

41a. Flowers white Rein Orchis, Habenaria dilatata.

41b. Flowers greenish-yellow — 42.

42a. Lip lanceolate, tapering toward the apex Rein Orchis, Habenaria hyperborea.

42b. Lip oblong, truncate at the apex Rein Orchis, Habenaria flava.

43a. Lip deeply 3-lobed, toothed or fringed — 44.

43b. Lip not 3-lobed, but deeply fringed — 46.

44a. Flowers purple Purple Fringed Orchis, Habenaria psycodes.

44b. Flowers white or nearly so — 45.

45a. Spur 3 cm. long or more Prairie Fringed Orchis, Habenaria leucophaea.

45b. Spur 1-1.5 cm. long Ragged Fringed Orchis, Habenaria lacera.

46a. Flowers yellow Yellow Fringed Orchis, Habenaria ciliaris.

46b. Flowers white White Fringed Orchis, Habenaria blephariglottis.

PIPERACEAE, the Pepper Family

Herbaceous plants with alternate leaves, and flowers without either calyx or corolla.

One species in Michigan, a marsh plant with heart-shape leaves and slender racemes of white flowers Lizard's Tail, Saururus cernuus.

SALICACEAE, the Willow Family

Trees or shrubs, with dioecious flowers in catkins.

1a. Leaves less than twice as long as broad, on petioles 3 cm. long or more — 2.

1b. Leaves more than twice as long as broad, on petioles 2.5 cm. long or less. (The genus Salix, or Willow, contains about 30 species in Michigan, of which only the commoner are mentioned here. For the others the Manuals should be consulted.) — 8.

2a. Petioles strongly flattened laterally — 3.

2b. Petioles not flattened laterally — 6.

3a. Leaves broadly ovate or nearly circular — 4.

3b. Leaves broadly triangular or deltoid in shape — 5.

4a. Leaves coarsely toothed Large-toothed Aspen, Populus grandidentata.

4b. Leaves finely crenulate or serrate Quaking Aspen, Populus tremuloides.

5a. Tree with narrow spire-shape crown Lombardy Poplar, Populus nigra var. italica.

5b. Tree with spreading crown Cottonwood, Populus deltoides.

6a. Lower side of leaf densely tomentose White Poplar, Populus alba.

6b. Lower side of leaf glabrous or nearly so — 7.

7a. Petioles glabrous Balsam Poplar, Populus balsamifera.

7b. Petioles ciliate Balm of Gilead, Populus candicans.

8a. Trees — 9.

8b. Shrubs — 13.

9a. Petioles without glands — 10.

9b. Petioles with glands — 11.

10a. Petiole short (about 5 mm.), broad and flat Black Willow, Salix nigra.

10b. Petiole slender, about 10-20 mm. long Peach-leaved Willow, Salix amygdaloides.

11a. Leaves green beneath Crack Willow, Salix fragilis.

11b. Leaves pale beneath — 12.

12a. Branches and twigs conspicuously drooping Weeping Willow, Salix babylonica.

12b. Branches and twigs not conspicuously drooping, yellow Yellow Willow, Salix alba var. vitellina.

13a. Shrubs of bogs — 14.

13b. Plants of sand-dunes along the Great Lakes — 15.

13c. Plants of dry upland hills — 16.

13d. Plants of wet ground, river-banks, and swamps — 17.

14a. Leaves densely white-tomentose beneath Willow, Salix candida.

14b. Leaves pale beneath but not tomentose Willow, Salix serissima.

14c. Leaves glabrous and green beneath Willow, Salix pedicellaris.

15a. Leaves linear Willow, Salix longifolia.

15b. Leaves ovate-lanceolate, tomentose beneath Willow, Salix syrticola.

15c. Leaves ovate-lanceolate, glabrous Willow, Salix glaucophylla.

16a. Leaves about 3 times as long as broad Willow, Salix rostrata.

16b. Leaves narrower, nearly sessile Willow, Salix tristis.

16c. Leaves narrower, distinctly petioled Willow, Salix humilis.

17a. Leaves linear or nearly so Willow, Salix longifolia.

17b. Leaves shining Willow, Salix lucida.

17c. Leaves silky Willow, Salix sericea.

17d. Leaves not as in the preceding 3 species — 18.

18a. Leaves rounded at base Willow, Salix cordata.

18b. Leaves acute at base — 19.

19a. Leaves finely serrulate Willow, Salix petiolaris.

19b. Leaves remotely serrate or nearly entire Willow, Salix discolor.

MYRICACEAE, the Sweet Gale Family

Shrubs, with monoecious or dioecious flowers in catkins, and aromatic foliage.

1a. Leaves pinnately lobed Sweet Fern, Myrica asplenifolia.

1b. Leaves merely serrate — 2.

2a. Shrub of sandy soil, shore of Lake Erie Bayberry, Myrica carolinensis.

2b. Shrub of bogs and shores, northern half of state Sweet Gale, Myrica gale.

JUGLANDACEAE, the Walnut Family

Trees with alternate pinnately compound leaves and flowers in catkins.

1a. Leaflets 11-23; pith divided by partitions into chambers — 2.

1b. Leaflets 5-11; pith not partitioned (Hickory) — 3.

2a. Pith brown; bark with flat longitudinal ridges Butternut, Juglans cinerea.

2b. Pith cream-color; bark of trunk without flat ridges Black Walnut, Juglans nigra.

3a. Bark of the trunk essentially smooth, not deeply furrowed or shaggy — 4.

3b. Bark of the trunk deeply furrowed or shaggy — 6.

4a. Leaflets glabrous beneath; buds greenish — 5.

4b. Leaflets somewhat pubescent beneath; buds bright yellow Bitter Nut, Carya cordiformis.

5a. Twigs hairy Small-fruited Hickory, Carya microcarpa.

5b. Twigs smooth Pignut Hickory, Carya glabra.

6a. Twigs and leaves both pubescent — 7.

6b. Twigs nearly smooth; leaves smooth beneath Shag-bark Hickory, Carya ovata.

7a. Twigs brownish; buds densely hairy Mocker-nut Hickory, Carya alba.

7b. Twigs orange; buds very slightly hairy King-nut Hickory, Carya laciniosa.

BETULACEAE, the Birch Family

Trees or shrubs with alternate simple leaves and inconspicuous monoecious flowers, the staminate flowers in catkins, and the pistillate in catkins or small clusters.

1a. Trees, with white or yellowish bark exfoliating in thin papery plates or scales — 2.

1b. Tree or shrub, with smooth, dark gray bark; trunk fluted with prominent longitudinal ridges Hornbeam, Carpinus caroliniana.

1c. Trees or shrubs; the bark more or less roughened, but not exfoliating; trunk not fluted — 3.

2a. Bark white or chalky Paper Birch, Betula alba var. papyrifera.

2b. Bark yellowish Yellow Birch, Betula lutea.

3a. Shrubs, with leaves 4 cm. long or less — 4.

3b. Shrubs or trees, with leaves 5 cm. long or more — 5.

4a. Twigs glandular-warty Dwarf Birch, Betula glandulosa.

4b. Twigs not glandular Swamp Birch, Betula pumila.

5a. Twigs and bark with the odor of wintergreen Sweet Birch, Betula lenta.

5b. Twigs and bark without odor of wintergreen — 6.

6a. Fruit clusters woody, persistent on the plant for a long time — 7.

6b. Fruit clusters herbaceous, dropping in late autumn — 9.

7a. Leaves rusty or whitish beneath, and pubescent at least on the veins Speckled Alder, Alnus incana.

7b. Leaves green beneath, and either pubescent or smooth — 8.

8a. Leaves broadest at or below the middle Mountain Alder, Alnus crispa.

8b. Leaves broadest above the middle Smooth Alder, Alnus rugosa.

9a. Tree; fruit a cluster of bladder-like sacs each containing a small achene Ironwood, Ostrya virginiana.

9b. Shrubs; fruit a nut within a close-fitting involucre — 10.

10a. Involucre of 2 broad bracts, almost separate and not much longer than the fruit Hazel, Corylus americana.

10b. Involucre of united bracts, prolonged into a bristly beak beyond the fruit Beaked Hazel, Corylus rostrata.

FAGACEAE, the Beech Family

Trees (or 1 species shrubby), with alternate simple leaves and monoecious flowers, the staminate flowers in catkins, and the pistillate solitary or in small clusters. Fruit a nut (or acorn) enclosed in a cup or bur.

1a. Leaves serrate with numerous sharp-pointed teeth — 2.

1b. Leaves serrate, lobed, or entire, but never serrate with sharp-pointed teeth; fruit an acorn; pith 5-angled in the young twigs (Oak) — 3.

2a. Bark gray, smooth; buds 3-4 times longer than wide; nut Beech, Fagus grandifolia.

2b. Bark rough; buds relatively thicker; nut rounded Chestnut, Castanea dentata.

3a. Leaves entire, except for a bristle at the tip Shingle Oak, Quercus imbricaria.

3b. Leaves toothed or lobed, the points bristle-tipped — 4.

3c. Leaves toothed or lobed, the points without bristles — 10.

4a. Leaves entire below the middle, with a few shallow lobes beyond Black Jack Oak, Quercus marilandica.

4b. Leaves deeply lobed throughout — 5.

5a. Cup of the acorn saucer-shape, covering less than one-third of the acorn — 6.

5b. Cup of the acorn hemispherical or top-shape, covering one-third or more of the acorn — 8.

6a. Length of the lateral leaf-lobes less than one-third the width of the leaf; acorn cup 2-2.5 cm. wide Red Oak, Quercus rubra.

6b. Length of the lateral leaf-lobes more than one-third the width of the leaf — 7.

7a. Acorn depressed-globose, about 1 cm. in diameter Pin Oak, Quercus palustris.

7b. Acorn ovoid, 1.5-2 cm. thick Schneck's Oak, Quercus schneckii.

8a. Leaves pubescent beneath Black Oak, Quercus velutina.

8b. Leaves glabrous beneath — 9.

9a. Buds glabrous; inner bark of the trunk yellow Hill's Oak, Quercus ellipsoidalis.

9b. Buds pubescent beyond the middle; inner bark of trunk red Scarlet Oak, Quercus coccinea.

10a. Leaves deeply pinnately lobed — 11.

10b. Leaves crenate, dentate, or sinuate, not lobed — 12.

11a. Leaf divided nearly to the middle by a pair of deep lateral lobes near the middle of the leaf; acorn more than half covered by the cup Bur Oak, Quercus macrocarpa.

11b. Leaf without a median pair of deeper lobes; acorn about one-fourth covered by the cup White Oak, Quercus alba.

12a. Leaves broadest at or near the middle, with numerous (8-13) sharp coarse teeth on each side Yellow Oak, Quercus muhlenbergii.

12b. Leaves broadest above the middle, with a few shallow, rounded or subacute teeth (7 or less on each side) — 13.

13a. Large tree; leaves densely white-tomentose beneath; acorn on a stalk 3-10 cm. long Swamp White Oak, Quercus bicolor.

13b. Shrub; leaves thinly white-tomentose beneath; acorn sessile or nearly so Scrub Oak, Quercus prinoides.

URTICACEAE, the Nettle Family

Herbs or trees, with small inconspicuous apetalous flowers.

1a. Trees or tall shrubs — 2.

1b. Herbs — 7.

2a. Leaves oblong-ovate to lanceolate, serrate — 3.

2b. Leaves broadly ovate to rotund, some of them lobed (Mulberry) — 6.

3a. Leaves thick, coarsely and doubly serrate, broadest near the middle (Elm) — 4.

3b. Leaves thin, simply serrate, broadest distinctly below the middle Hackberry, Celtis occidentalis.

4a. Some of the branches with flat corky wings; leaves smooth above Cork Elm, Ulmus racemosa.

4b. Branches without corky wings; leaves more or less rough above — 5.

5a. Petioles and axillary buds glabrous White Elm, Ulmus americana.

5b. Petioles and axillary buds pubescent with rusty hairs Slippery Elm, Ulmus fulva.

6a. Leaves rough above Red Mulberry, Morus rubra.

6b. Leaves smooth above White Mulberry, Morus alba.

7a. Leaves alternate — 8.

7b. Leaves opposite — 9.

8a. Leaves 2-5 cm. long, stems pubescent Pellitory, Parietaria pennsylvanica.

8b. Leaves 8-20 cm. long; stem armed with stinging hairs Wood Nettle, Laportea canadensis.

9a. Twining plant; leaves serrate or cleft Hop, Humulus lupulus.

9b. Erect plant; leaves palmately compound Hemp, Cannabis sativa.

9c. Erect plants; leaves not lobed or compound — 10.

10a. Stems armed with stinging hairs — 11.

10b. Stems glabrous or rough, but not with stinging hairs — 12.

11a. Leaves ovate, with a heart-shape base Stinging Nettle, Urtica dioica.

11b. Leaves lanceolate or ovate-lanceolate, not heart-shape at base Slender Nettle, Urtica gracilis.

12a. Stems glabrous, pellucid Clearweed, Pilea pumila.

12b. Stems rough, opaque False Nettle, Boehmeria cylindrica.

SANTALACEAE, the Sandalwood Family

Low herbs with alternate entire leaves and terminal clusters of small greenish-white bell-shape flowers without petals in spring and early summer.

1a. Inflorescence of several-flowered clusters terminating the stem and in the upper axils Toad-flax, Comandra umbellata.

1b. Inflorescence of axillary clusters of 1-5 flowers Toad-flax, Comandra livida.

LORANTHACEAE, the Mistletoe Family

Parasitic plants, attached to the branches of trees.

One species in Michigan, a dwarf brown plant 5-20 mm. long, with minute scale-like leaves, growing on the branches of Black Spruce Dwarf Mistletoe, Arceuthobium pusillum.

ARISTOLOCHIACEAE, the Birthwort Family

Flowers greenish-brown or reddish-brown, at or near the ground, with inferior 6-celled ovary.

1a. Leaves alternate, on the stem; flowers on a basal scaly branch (1-4 dm. high; summer) Virginia Snakeroot, Aristolochia serpentaria.

1b. Leaves a single basal pair, bearing 1 short-stalked flower between them (spring) (Wild Ginger) — 2.

2a. Lobes of the perianth ending in a tubular portion 5-8 mm. long Wild Ginger, Asarum canadense.

2b. Lobes of the perianth ending in a tubular portion over 1 cm. long Wild Ginger, Asarum canadense var. acuminatum.

2c. Lobes of the perianth triangular, not tubular at the end Wild Ginger, Asarum canadense var. reflexum.

POLYGONACEAE, the Buckwheat Family

Herbs with alternate entire leaves, stipules surrounding the stem above the base of each leaf, and small green, white or pink flowers without petals.

1a. Erect or ascending or prostrate or floating plants — 2.

1b. Scrambling or climbing plants, clinging by sharp recurved prickles on the 4-angled stems (flowers greenish or pink, summer) (Tear-thumb) — 32.

1c. Twining vines (flowers white or greenish, summer) — 33.

2a. Sepals 6, the 3 inner ones enlarging in fruit and surrounding the achenes; flowers in panicles — 3.

2b. Sepals 4 or 5 (occasional flowers may be found with 6 sepals, but the flowers are not in panicles) (summer) — 13.

3a. Leaves arrow-shape or halberd-shape, with 2 basal lobes (Sorrel) — 4.

3b. Leaves without basal lobes (Dock) — 5.

4a. Leaves halberd-shape, the basal lobes directed sidewise Red Sorrel, Rumex acetosella.

4b. Leaves arrow-shape, the basal lobes directed backward Green Sorrel, Rumex acetosa.

5a. The projecting wings of the fruiting calyx (known as valves) with sharp slender teeth Bitter Dock, Rumex obtusifolius.

5b. Valves entire or finely dentate, but without sharp slender teeth — 6.

6a. Pedicels straight, thickened toward the end, all regularly deflexed, 3-4 times longer than the fruiting calyx Swamp Dock, Rumex verticillatus.

6b. Pedicels slender, flexuous, spreading — 7.

7a. Leaves flat or nearly so — 8.

7b. Leaves with strongly crisped or wavy-curled margins; plants usually of cultivated grounds or waste places (5-10 dm., summer) — 12.

8a. With grain-like tubercles on all 3 valves of the fruit — 9.

8b. With grain-like tubercles on only one valve, or entirely lacking — 10.

9a. Valves broadly cordate, finely toothed Water Dock, Rumex brittanica.

9b. Valves triangular-ovate, entire or nearly so Dock, Rumex mexicanus.

10a. Valves oblong Bloody Dock, Rumex sanguineus.

10b. Valves broadly heart-shape — 11.

11a. Grain-like tubercle less than half as long as the valve Patience Dock, Rumex patientia.

11b. Grain-like tubercle more than half as long as the valve Tall Dock, Rumex altissimus.

12a. The grain-like tubercle on the valves of the fruit broadly ellipsoid, with rounded apex Sour Dock, Rumex crispus.

12b. Tubercle ovoid with tapering apex Sour Dock, Rumex elongatus.

13a. Flowers inconspicuous, in small axillary clusters; leaves jointed at the base (Knotweed) — 14.

13b. Flowers more or less conspicuous, in obvious spikes or racemes which terminate the stems or branches, or arise from the axils of the upper leaves — 18.

14a. Leaves sharply folded lengthwise (1-4 dm. tall) Knotweed, Polygonum tenue.

14b. Leaves flat or nearly so — 15.

15a. The small sepals pink or white at the margin (stems prostrate or ascending) — 16.

15b. Sepals greenish or yellowish throughout (stems erect or ascending) — 17.

16a. Leaves thin; common weed of dooryards and gardens Knotweed, Polygonum aviculare.

16b. Leaves thick and fleshy; a plant of sandy shores Knotweed, Polygonum aviculare var. littorale.

17a. Leaves narrowly lanceolate or linear-oblong; rare species Knotweed, Polygonum ramosissimum.

17b. Leaves broadly oblong, oval, or elliptical; common weed of yards and gardens Knotweed, Polygonum erectum.

18a. Leaves broadly triangular (3-7 dm. high; flowers white) Buckwheat, Fagopyrum esculentum.

18b. Leaves from linear to ovate or oblong — 19.

19a. Sepals 4; flowers in very long and slender spike-like racemes (4-10 dm. high) Knotweed, Polygonum virginianum.

19b. Sepals 5; flowers in spikes or racemes — 20.

20a. Flowers on slender pedicels, forming a loose raceme; leaves linear, jointed at the base (1-3 dm. high; flowers pink or white; chiefly near the Great Lakes) Jointweed, Polygonella articulata.

20b. Flowers sessile or nearly so, forming a spike or spike-like raceme — 21.

21a. Stipular sheaths at the base of the leaves ciliate at their upper margin — 22.

21b. Stipular sheaths not ciliate at the upper margin — 28.

22a. Sheaths with spreading borders — 23.

22b. Sheaths without a spreading border, appressed to the stem (Smartweed) — 24.

23a. Leaves ovate, acuminate; stem erect (1-2 m. high; flowers pink) Prince's Feather, Polygonum orientate.

23b. Leaves oblong, obtuse or subacute; spreading or ascending plant of wet soil Water Smartweed, Polygonum amphibium var. hartwrightii.

24a. Peduncles with glandular hairs (5-15 dm. high) Smartweed, Polygonum careyi.

24b. Peduncles not glandular (1-8 dm. high) (Smartweed) — 25.

25a. Sepals beset with minute black dots — 26.

25b. Sepals white, pink, or red, not black-dotted — 27.

26a. Racemes drooping or nodding at the tip; achene dull-colored Smartweed, Polygonum hydropiper.

26b. Racemes erect; achene smooth and shining Smartweed, Polygonum acre.

27a. Sheaths smooth; leaves usually with a dark spot near the base Smartweed, Polygonum persicaria.

27b. Sheaths hairy; leaves not dark-spotted Smartweed, Polygonum hydropiperoides.

28a. Leaves obtuse or somewhat acute at the apex — 29.

28b. Leaves acuminate at the apex (5-15 dm. high; flowers white to pink) (Smartweed) — 30.

29a. Stem unbranched, erect, bearing a single terminal raceme (5-30 cm. high; flowers pink) Bistort, Polygonum viviparum.

29b. Stem branched, submerged in water or creeping on muddy shores (flowers pink) Water Smartweed, Polygonum amphibium.

30a. Raceme single or two; leaves broadly ovate-lanceolate, about 3 times as long as wide Smartweed, Polygonum muhlenbergii.

30b. Racemes numerous; leaves lanceolate, 4-6 times as long as wide — 31.

31a. Racemes drooping or nodding at the tip Smartweed, Polygonum lapathifolium.

31b. Racemes erect Smartweed, Polygonum pennsylvanicum.

32a. Leaves arrow-shape, the basal lobes pointing backward Tear-thumb, Polygonum sagittatum.

32b. Leaves halberd-shape, the basal lobes pointing sidewise Tear-thumb, Polygonum arifolium.

33a. The three outer sepals becoming conspicuously winged in fruit (False Buckwheat) — 34.

33b. The sepals all unchanged in fruit, except in size (Black Bindweed) — 35.

34a. Wings of the fruit with wavy-curled margins False Buckwheat, Polygonum scandens.

34b. Wings of the fruit flat False Buckwheat, Polygonum dumetorum.

35a. Leaf-sheaths with a ring of bristles at the base Black Bindweed, Polygonum cilinode.

35b. Leaf-sheaths without a ring of bristles Black Bindweed, Polygonum convolvulus.

CHENOPODIACEAE, the Goosefoot Family

Herbs, with inconspicuous greenish or reddish flowers without petals, in summer.

1a. Leaves linear or nearly so, entire — 2.

1b. Leaves of a broader shape, usually toothed or lobed — 5.

2a. Leaves rather stiff, narrowly linear or thread-like, with spine-like tips Russian Thistle, Salsola kali var. tenuifolia.

2b. Leaves soft, not spine-like — 3.

3a. Widely branched, rather diffuse, 1-5 dm. tall; plant of the shore of the Great Lakes Bug-seed, Corispermum hyssopifolium.

3b. Erect plants with ascending branches — 4.

4a. Leaves glabrous (3-6 dm. tall) Goosefoot, Chenopodium leptophyllum.

4b. Leaves minutely ciliate on the margin (bushy branched, 5-10 dm. tall) Kochia, Kochia scoparia.

5a. Principal leaves with a broad truncate, rounded, or hastate base — 6.

5b. Principal leaves narrowed to the base — 12.

6a. Leaves broadly ovate, with 1-4 large sharp projecting teeth on each side Goosefoot, Chenopodium hybridum.

6b. Leaves hastate or triangular-ovate, entire or with many teeth — 7.

7a. Leaves entire or merely undulate — 8.

7b. Leaves sharply or sinuately toothed — 9.

8a. Stem erect, simple or sparingly branched Good King Henry, Chenopodium bonus-henricus.

8b. Stem diffuse or ascending, freely branched Orache, Atriplex patula.

9a. Flowers in small heads, in the axils or in terminal spikes; leaves sinuately toothed or nearly entire Strawberry Blite, Chenopodium capitatum.

9b. Flowers in terminal panicles; leaves sharply toothed (Goosefoot) — 10.

10a. Panicles short, not as long as the subtending leaves Goosefoot, Chenopodium murale.

10b. Panicles long, exceeding the subtending leaves — 11.

11a. Calyx green Goosefoot, Chenopodium urbicum.

11b. Calyx red Goosefoot, Chenopodium rubrum.

12a. Foliage glandular and strongly aromatic — 13.

12b. Foliage not glandular nor aromatic; sometimes ill-scented — 15.

13a. Flowers in large loose open spreading panicles; leaves deeply pinnatifid Jerusalem Oak, Chenopodium botrys.

13b. Flowers clustered in slender axillary or terminal spikes — 14.

14a. Spikes dense, leafy Mexican Tea, Chenopodium ambrosioides.

14b. Spikes open, nearly leafless Wormseed, Chenopodium ambrosioides var. anthelminticum.

15a. Stem erect, 5-20 dm. tall; leaves frequently white-mealy Lamb's Quarters, Chenopodium album.

15b. Stem prostrate or ascending, succulent; leaves glaucous-white beneath Goosefoot, Chenopodium glaucum.

15c. Stem widely and diffusely branched; leaves green, soon deciduous Cycloloma, Cycloloma atriplicifolium.

AMARANTHACEAE, the Amaranth Family

Herbs, with alternate leaves, and inconspicuous greenish or reddish flowers without petals, which are axillary or in dense clusters, blooming in summer.

1a. Flower-clusters axillary — 2.

1b. Flower-clusters in terminal spikes or panicles, sometimes also axillary — 3.

2a. Plant prostrate or decumbent; seed about 1.5 mm. broad Pigweed, Amaranthus blitoides.

2b. Plant erect or ascending, widely branched; seeds about 1 mm. broad (3-10 dm. high) Tumble Weed, Amaranthus graecizans.

3a. Principal leaves with a pair of spines at their base Thorny Amaranth, Amaranthus spinosus.

3b. Spines none at the base of the leaves — 4.

4a. Weedy plants of cultivated or waste ground; flowers monoecious or polygamous; pistillate flowers with a calyx (Pigweed) — 5.

4b. Plants of swamps or stream-banks; flowers dioecious; pistillate flowers without calyx (Water Hemp) — 7.

5a. Spikes short, 1-8 cm. long, crowded in dense ovoid panicles; the terminal spike not conspicuously elongated beyond the appressed or ascending lower ones Pigweed, Amaranthus retroflexus.

5b. Spikes slender, 1-12 cm. long; the terminal spike greatly exceeding the short inconspicuous divergent lower ones — 6.

6a. Bracts subulate, sharply awned Pigweed, Amaranthus hybridus.

6b. Bracts merely acuminate Pigweed, Amaranthus paniculatus.

7a. Flowers in leafy spikes, or the lower in separate clusters Water Hemp, Acnida tuberculata.

7b. Flowers in separate distinct clusters Water Hemp, Acnida tuberculata var. subnuda.

PHYTOLACCACEAE, the Pokeweed Family

Herbs with alternate entire leaves, small flowers without petals, and a many-celled ovary.

One species in Michigan, 1-2 m. high, with numerous racemes of whitish flowers, in late summer, followed by dark-purple berries Pokeweed, Phytolacca decandra.

NYCTAGINACEAE, the Four-o'Clock Family

Herbs, with opposite entire leaves and flowers in small clusters surrounded by a broad open calyx-like involucre; the true calyx colored like a corolla; petals none (4-8 dm. high; flowers purple, in summer).

1a. Leaves lanceolate or narrower, sessile Umbrella-wort, Oxybaphus hirsutus.

1b. Leaves ovate, petioled Umbrella-wort, Oxybaphus nyctagineus.

ILLECEBRACEAE, the Knotwort Family

Herbs, with opposite entire leaves, and minute flowers without petals. (Prostrate spreading or freely branched plants, 3 dm. high or less; flowers in summer.)

1a. Stipules none; leaves slightly connate at base, subulate Knawel, Scleranthus annuus.

1b. Stipules present, but small; leaves elliptical or oval (Forked Chickweed) — 2.

2a. Stems pubescent; internodes seldom more than 1 cm. long Forked Chickweed, Anychia polygonoides.

2b. Stems smooth; internodes about 2 cm. long Forked Chickweed, Anychia canadensis.

AIZOACEAE, the Carpet-weed Family

Prostrate herbs, with whorled leaves and small whitish axillary flowers without petals, in summer.

One species in Michigan Carpet-weed, Mollugo verticillata.

CARYOPHYLLACEAE, the Pink Family

Herbs, with opposite or whorled entire leaves, and stems frequently swollen at the nodes. Sepals 4 or 5; petals separate, as many as the sepals, or rarely none; stamens twice as many as the petals in plants with conspicuous flowers, sometimes fewer in those with small flowers; ovary 1-celled, with the ovules on a central axis, and with 2-5 styles.

1a. Calyx spreading, of separate sepals; flowers 15 mm. wide or less; petals sometimes none — 2.

1b. Calyx tubular, of united sepals; flowers in many species more than 15 mm. wide; petals always present — 22.

2a. Stipules present — 3.

2b. Stipules none — 4.

3a. Leaves opposite; flowers pink (about 1 dm. high; summer) Sand Spurrey, Spergularia rubra.

3b. Leaves whorled; flowers white (1-5 dm. high; leaves linear; summer) Spurrey, Spergula arvensis.

4a. Leaves subulate or thread-like — 5.

4b. Leaves linear to ovate — 7.

5a. Leaves opposite (1 dm. high or less; flowers white, summer) Pearlwort, Sagina procumbens.

5b. Leaves fascicled in the axils — 6.

6a. Styles 4 or 5 (1 dm. high; terminal white flowers 5 mm. wide, in summer) Pearlwort, Sagina nodosa.

6b. Styles 3 (1-4 dm. high; flowers white, nearly 1 cm. wide, summer) Stitchwort, Arenaria stricta.

7a. Petals entire (3 dm. high or less; flowers white, in summer) (Stitchwort) — 8.

7b. Petals notched or 2-cleft at the end, or none — 11.

8a. Principal leaves 1 cm. long or less — 9.

8b. Principal leaves 1.5 cm. long or more — 10.

9a. Petals half as long as the sepals Stitchwort, Arenaria leptoclados.

9b. Petals almost as long as the sepals Stitchwort, Arenaria serpyllifolia.

10a. Leaves oblong-oval, obtuse. Stitchwort, Arenaria lateriflora.

10b. Leaves lanceolate, acute. Stitchwort, Arenaria macrophylla.

11a. Capsule splitting by valves at maturity; styles usually 3 (Chickweed) — 12.

11b. Capsule opening by terminal teeth at maturity; styles usually 5 (tufted or matted plants, 1-5 dm. high; flowers white, in spring and summer) (Mouse-ear Chickweed) — 18.

12a. Petals distinctly shorter than the sepals, or none — 13.

12b. Petals as long as the sepals, or longer — 15.

13a. Leaves ovate (1-3 dm. high; flowers white, all summer) Chickweed, Stellaria media.

13b. Leaves lanceolate to oblong (in water or wet places, 1-4 dm. high; flowers white, in summer) — 14.

14a. Flowers in a leafy terminal branching cluster Chickweed, Stellaria borealis.

14b. Flowers in a lateral cluster with minute bracts Chickweed, Stellaria uliginosa.

15a. Flowers in clusters with leaf-like bracts, or axillary and solitary (in water or wet places; 1-3 dm. high; flowers white, summer) Chickweed, Stellaria crassifolia.

15b. Flowers in clusters with scale-like bracts — 16.

16a. Leaves distinctly linear; cymes lateral; a common species in marshes (2-5 dm. high; flowers white, early summer) Chickweed, Stellaria longifolia.

16b. Leaves distinctly broadest near the base; flower-cluster terminal — 17.

17a. Pedicels erect; clusters usually few-flowered; in extreme northern part of the state only (1-3 dm. high; flowers white, summer) Chickweed, Stellaria longipes.

17b. Pedicels spreading; clusters open, many-flowered (2-6 dm. high; flowers white, in summer) Chickweed, Stellaria graminea.

18a. Petals distinctly longer than the sepals — 19.

18b. Petals as long as the sepals, or shorter than them — 21.

19a. Flowers much less than 1 cm. wide Mouse-ear Chickweed, Cerastium nutans.

19b. Flowers more than 1 cm. wide — 20.

20a. Stem-leaves linear or narrowly lanceolate Mouse-ear Chickweed, Cerastium arvense.

20b. Stem-leaves oblong Mouse-ear Chickweed, Cerastium arvense var. oblongifolium.

21a. Bracts green; pedicels short and inflorescence crowded Mouse-ear Chickweed, Cerastium viscosum.

21b. Bracts with transparent white margins; pedicels longer than the calyx and inflorescence open Mouse-ear Chickweed, Cerastium vulgatum.

22a. Styles 5 — 23.

22b. Styles 3 (3-10 dm. high; flowers in summer) — 25.

22c. Styles 2 — 29.

23a. Calyx-teeth much longer than the calyx-tube (erect, 4-10 dm. high; flowers large, red, late summer) Corn Cockle, Agrostemma githago.

23b. Calyx-teeth shorter than the calyx-tube (4-10 dm. high; flowers in summer) — 24.

24a. Flowers crimson Mullein Pink, Lychnis coronaria.

24b. Flowers white or pink White Campion, Lychnis alba.

25a. Flowers night-blooming, always wilted during the day Catchfly, Silene noctiflora.

25b. Flowers open during the day — 26.

26a. Flowers 6 mm. wide or less, white or pink Catchfly, Silene antirrhina.

26b. Flowers 1-2 cm. wide, white to pink or purple — 27.

26c. Flowers 2 cm. wide or more, crimson Fire Pink, Silene virginica.

27a. Principal leaves in whorls of 4 Starry Campion, Silene stellata.

27b. Leaves opposite — 28.

28a. Calyx globular, much inflated or bladder-like Bladder Campion, Silene latifolia.

28b. Calyx club-shape, not inflated Sweet William Catchfly, Silene armeria.

29a. Leaves linear or narrowly lanceolate, 5 mm. wide or less (flowers pink or white, in summer) — 30.

29b. Leaves lanceolate or ovate (flowers pink, white, or red, in summer) — 32.

30a. Flowers in terminal clusters; leaves hairy (2-4 dm. high) Deptford Pink, Dianthus armeria.

30b. Flowers solitary at the ends of long pedicels — 31.

31a. Flowers 3-4 mm. wide (1-2 dm. high) Gypsophyll, Gypsophila muralis.

31b. Flowers 1 cm. wide or more (1-5 dm. high) Meadow Pink, Dianthus deltoides.

32a. Flowers less than 1 cm. broad — 33.

32b. Flowers more than 1 cm. broad — 34.

33a. Flowers white, in large panicles (4-7 dm. high) Baby's Breath, Gypsophila paniculata.

33b. Flowers pale red, in loose clusters (4-10 dm. high) Cowherb, Saponaria vaccaria.

34a. Leaves with 3-5 prominent veins (4-7 dm. high) Soapwort, Saponaria officinalis.

34b. Leaves with one mid-vein (3-6 dm. high) Sweet William, Dianthus barbatus.

PORTULACACEAE, the Purslane Family

Herbs with opposite or alternate leaves and regular flowers with 2 sepals, 5 petals, and a 1-celled ovary with 2 or 3 styles.

1a. Leaves a single pair on each stem (1-2 dm. high; flowers pink, in racemes in early spring) (Spring Beauty) — 2.

1b. Leaves numerous (prostrate or spreading; flowers in summer) — 3.

2a. Leaves lance-ovate to oblong, not more than six times as long as wide Spring Beauty, Claytonia caroliniana.

2b. Leaves linear or linear-lanceolate, more than six times as long as wide Spring Beauty, Claytonia virginica.

3a. Flowers yellow, about 5 mm. wide Purslane, Portulaca oleracea.

3b. Flowers 2-5 cm. wide Portulaca, Portulaca grandiflora.

CERATOPHYLLACEAE, the Hornwort Family

Submerged aquatics, with whorled, finely dissected leaves and inconspicuous flowers with neither calyx nor corolla.

One species in Michigan Hornwort, Ceratophyllum demersum.

NYMPHAEACEAE, the Water Lily Family

Aquatic plants, with usually large and floating leaves which are round or elliptical and palmately veined.

1a. Floating and emersed leaves centrally peltate — 2.

1b. Leaves rounded but not peltate, with a deep sinus — 3.

2a. Leaves round, 3 dm. in diameter or more; flowers very large, pale yellow Lotus, Nelumbo lutea.

2b. Leaves oval, 5-15 cm. long; flowers small, purple Water Shield, Brasenia schreberi.

3a. Flowers yellow (Pond Lily) — 4.

3b. Flowers white or tinged with pink (Water Lily) — 5.

4a. Leaves more than 1 dm. long Pond Lily, Nymphaea advena.

4b. Leaves less than 1 dm. long Pond Lily, Nymphaea microphylla.

5a. Flowers very fragrant; leaves purplish beneath Water Lily, Castalia odorata.

5b. Flowers not fragrant; leaves green beneath Water Lily, Castalia tuberosa.

RANUNCULACEAE, the Crowfoot Family

Herbs with alternate (rarely opposite) leaves, acrid watery juice, separate sepals and petals, numerous stamens, and several or many (rarely only 1) simple pistils. Petals present or absent, in the latter case the sepals are usually petal-like in appearance.

1a. Climbing plants with opposite leaves (flowers in late summer) (Virgin's Bower) — 2.

1b. Aquatic plants with dissected submerged leaves (flowers in late spring and summer) (Water Crowfoot) — 3.

1c. Terrestrial or mud plants, not agreeing with 1a or 1b — 6.

2a. Flowers white, 2-3 cm. wide Virgin's Bower, Clematis virginiana.

2b. Flowers pink-purple, 5-8 cm. wide Virgin's Bower, Clematis verticillaris.

3a. Flowers white — 4.

3b. Flowers yellow — 5.

4a. Leaves rigid, not collapsing when removed from the water Water Crowfoot, Ranunculus circinatus.

4b. Leaves soft, collapsing when removed from the water Water Crowfoot, Ranunculus aquatilis var. capillaceus.

5a. Submerged leaves divided into hair-like segments Water Crowfoot, Ranunculus delphinifolius.

5b. Submerged leaves palmately divided into linear lobes Water Crowfoot, Ranunculus purshii.

6a. Flowers blue, irregular, with one spur (4-8 dm. high, summer) Larkspur, Delphinium ajacis.

6b. The five petals each prolonged into a spur; flowers showy (4-8 dm. tall) (Columbine) — 7.

6c. Flowers regular, without spurs — 8.

7a. Spurs nearly straight; flowers scarlet and yellow (spring) Wild Columbine, Aquilegia canadensis.

7b. Spurs strongly incurved; flowers blue or white (spring, early summer) Columbine, Aquilegia vulgaris.

8a. Flowers yellow — 9.

8b. Flowers of various colors, but never yellow — 28.

9a. Petals none; sepals petal-like; leaves crenate or dentate (2-4 dm. high, flowers in early spring) Cowslip, Caltha palustris.

9b. Petals small; sepals petal-like; leaves deeply palmately lobed (4-6 dm. tall; flowers in late spring) Globe-flower, Trollius laxus.

9c. Petals yellow; sepals green or yellowish — 10.

10a. Leaves linear to narrowly oblong, entire or with minute teeth (flowers 10-15 mm. wide, in summer) — 11.

10b. Leaves broader, some or all of them lobed or divided, or cordate-ovate and not lobed — 12.

11a. Stems ascending (4-8 dm. high), rooting at the lower joints; fruits pointed with a long slender beak Spearwort, Ranunculus laxicaulis.

11b. Stems prostrate and trailing, rooting at the joints; fruits tipped with a minute short beak Spearwort, Ranunculus flammula var. reptans.

12a. Basal leaves, or most of them, merely serrate or crenate, and not obviously lobed — 13.

12b. All the leaves lobed or divided — 16.

13a. Stem-leaves resembling the basal ones, and not lobed (1-2 dm. high; summer) Sea-side Crowfoot, Ranunculus cymbalaria.

13b. Stem-leaves deeply divided into oblong or linear segments — 14.

14a. Flowers 1.5 cm. wide or more (1-3 dm. high; spring) Buttercup, Ranunculus rhomboideus.

14b. Flowers 1 cm. wide or less (2-5 dm. high; spring) — 15.

15a. Foliage glabrous or minutely pubescent; basal leaves cordate Small-flowered Crowfoot, Ranunculus abortivus.

15b. Foliage villous; basal leaves barely cordate or not at all Small-flowered Crowfoot, Ranunculus micranthus.

16a. Stem erect or essentially so — 17.

16b. Stem prostrate, creeping, or ascending. Early in spring stems may be found which appear almost erect. Common spring-flowering buttercups are all classified here — 22.

17a. Flowers 2 cm. broad or larger (Buttercup) — 18.

17b. Flowers 1 cm. broad or smaller — 19.

18a. Terminal lobe of leaf stalked (2-5 dm. high, early summer) Buttercup, Ranunculus bulbosus.

18b. Terminal lobe of leaf sessile (5-10 dm. high; all summer) Buttercup, Ranunculus acris.

19a. Plant glabrous, succulent; stem hollow (1-5 dm. high; spring and summer) Cursed Crowfoot, Ranunculus sceleratus.

19b. Plant pubescent (Buttercup) — 20.

20a. Fruits tipped with a prominent recurved beak; plant of shady woods (2-6 dm. high; flowers in late spring) Buttercup, Ranunculus recurvatus.

20b. Fruits tipped with a straight or slightly curved beak; plants of marshes or wet soil (3-6 dm. high; flowers in summer) — 21.

21a. Fruits in a short-cylindric head on a conical receptacle Buttercup, Ranunculus pennsylvanicus.

21b. Fruits in a globose or short-ovoid head, on an obovoid receptacle Buttercup, Ranunculus macounii.

22a. Leaves dissected into numerous linear or narrowly wedge-shape divisions; plants growing in water or very wet places (late spring and summer) Water Crowfoot, Ranunculus delphinifolius.

22b. Leaves palmately lobed, the terminal division not definitely stalked — 23.

22c. Leaves compound, some or all of the divisions on definite stalks (Buttercup) — 24.

23a. Stem-leaves numerous (1-2 dm. tall; late spring and summer) Crowfoot, Ranunculus purshii.

23b. Stem-leaves one or none, the principal leaves all basal (about 1 dm. high; flowers in summer) Buttercup, Ranunculus lapponicus.

24a. Style short, obviously curved — 25.

24b. Style long and slender, straight or nearly so (common spring-flowering buttercups, 2-5 dm. high) — 26.

25a. Stems creeping; flowers 2 cm. wide or more (spring) Buttercup, Ranunculus repens.

25b. Stems ascending; flowers 1.5 cm. wide or less (3-6 dm. high; summer) Buttercup, Ranunculus macounii.

26a. The two lateral divisions of the leaf sessile or nearly so Buttercup, Ranunculus fascicularis.

26b. The two lateral divisions of the leaf on long stalks — 27.

27a. Roots fibrous; plants of wet soil Buttercup, Ranunculus septentrionalis.

27b. Roots thickened; plants of dry woods or thickets Buttercup, Ranunculus hispidus.

28a. Leaves dissected into numerous narrowly linear acute divisions (4-7 dm. high; flowers large, bluish, in summer) Love-in-a-mist, Nigella damascena.

28b. Leaves lobed or divided, but the divisions not separated by definite stalks — 29.

28c. Leaves truly compound, all their divisions separated by distinct stalks — 39.

29a. Leaves all basal, their lobes (usually 3) entire (1-2 dm. high; flowers pink-purple, in earliest spring) (Hepatica) — 30.

29b. Lobes of the leaf serrate or incised — 31.

30a. Lobes of the leaf obtuse or rounded Hepatica, Hepatica triloba.

30b. Lobes of the leaf acute Hepatica, Hepatica acutiloba.

31a. Petals none; sepals 3, usually falling away as soon as the flower opens (2-4 dm. high; flowers greenish-white, in spring) Golden Seal, Hydrastis canadensis.

31b. Petals none; sepals petal-like, 4 or more (Anemone) — 32.

31c. Petals present, but much smaller than the 5 petal-like sepals — 38.

32a. Stem-leaves sessile or nearly so — 33.

32b. Stem-leaves on definite petioles — 35.

33a. Ovary tipped with a long slender hairy style; flowers bluish-purple (1-4 dm. high; early spring) Pasque Flower, Anemone patens var. wolfgangiana.

33b. Ovary with a short style, densely woolly; flowers red, greenish, or white (1-4 dm. high; late spring and summer) — 34.

33c. Ovary tipped with a short style, glabrous or nearly so; flowers white (4-7 dm. high; late spring and early summer) Anemone, Anemone canadensis.

34a. Stem 1-flowered, sepals white Anemone, Anemone parviflora.

34b. Stem 3-flowered; sepals usually red Anemone, Anemone multifida.

35a. Achenes densely woolly; flowers appearing in summer — 36.

35b. Achenes merely pubescent; stems 1-flowered; woodland species blooming in early spring (1-2 dm. high; flowers white) Wood Anemone, Anemone quinquefolia.

36a. Segments of the leaf broadly wedge-shape or ovate; flowers white (4-8 dm. high) — 37.

36b. Segments of the leaf linear-oblong; flower red, greenish, or white; plants growing on the shores of the Great Lakes Anemone, Anemone multifida.

37a. Segments of the basal leaves wedge-lanceolate; head of fruit cylindric Anemone, Anemone cylindrica.

37b. Segments of the basal leaves ovate-lanceolate; head of fruit ovoid or oblong Anemone, Anemone virginiana.

38a. Stem-leaves present — 9b.

38b. Leaves all basal (1-2 dm. high; leaves 3-divided; flowers white, in early summer) Gold-thread, Coptis trifolia.

39a. Flowers numerous, in branching panicles (Meadow Rue) — 40.

39b. Flowers numerous, in racemes — 43.

39c. Flowers solitary or few, in loose clusters; woodland plants blooming in early spring (1-3 dm. high; flowers white to purple) — 45.

40a. Blooming in spring; stem-leaves with obvious petioles (3-7 dm. high; flowers white or greenish) Meadow Rue, Thalictrum dioicum.

40b. Blooming in late spring or summer, stem-leaves sessile or nearly so (8-15 dm. high; flowers white) — 41.

41a. Filaments club-shape, approximately as wide as the anther Meadow Rue, Thalictrum polygamum.

41b. Filaments slender or thread-like — 42.

42a. Leaves minutely pubescent beneath, but not glandular Meadow Rue, Thalictrum dasycarpum.

42b. Leaves minutely glandular beneath Meadow Rue, Thalictrum revolutum.

43a. Racemes slender, 10-90 cm. long (8-15 dm. high; flowers white, in summer) Bugbane, Cimicifuga racemosa.

43b. Racemes short and stout, 3-8 cm. long (4-8 dm. high; flowers white, in late spring) (Baneberry) — 44.

44a. Berries white; pedicels strongly thickened at maturity Baneberry, Actaea alba.

44b. Berries red; pedicels slender Baneberry, Actaea rubra.

45a. Flowers white; stem-leaves alternate Isopyrum, Isopyrum biternatum.

45b. Flowers white to pink or purplish; stem-leaves whorled Rue Anemone, Anemonella thalictroides.

MAGNOLIACEAE, the Magnolia Family

Trees or shrubs, with alternate leaves, and large, frequently showy flowers.

One species in Michigan, with broad 4-lobed leaves and greenish-yellow flowers in late spring Tulip Tree, Liriodendron tulipifera.

ANONACEAE, the Custard Apple Family

Trees or shrubs, with alternate simple entire leaves, 3 sepals, and 6 petals.

One species in Michigan; tall shrub or small tree, with obovate leaves and large dull-purple flowers in spring Papaw, Asimina triloba.

MENISPERMACEAE, the Moonseed Family

Woody climbers, with alternate leaves, 6-8 petals, and numerous stamens.

One species in Michigan, with 5-7-angled leaves which are peltate near the edge, and small white flowers in early summer Moonseed, Menispermum canadense.

BERBERIDACEAE, the Barberry Family

Shrubs or herbs; petals 6 or more; stamens 6-18, frequently opening by two terminal lids; pistil 1.

1a. Leaves simple — 2.

1b. Leaves compound — 3.

2a. Stem shrubby (flowers yellow, in racemes, in spring) Barberry, Berberis vulgaris.

2b. Stem herbaceous, with a single pair of palmately lobed leaves (4-6 dm. tall; flower white, solitary, terminal, in spring) May Apple, Podophyllum peltatum.

3a. Leaves all basal; leaflets 2 (2-4 dm. high; the flower-stalks bearing solitary white flowers in spring) Twin-leaf, Jeffersonia diphylla.

3b. The stem-leaf ternately compound, with numerous leaflets (4-8 dm. high; with yellowish-green clustered flowers in spring) Blue Cohosh, Caulophyllum thalictroides.

LAURACEAE, the Laurel Family

Trees or shrubs, with aromatic taste or odor, and alternate simple leaves; flowers small, imperfect, the anthers opening by lids.

1a. Freely branched shrub; leaves obovate-oblong, entire (flowers yellow, in early spring, before the leaves) Spice Bush, Benzoin aestivale.

1b. Tree or tall shrub; some or all of the leaves 2-3-lobed (flowers greenish-yellow, appearing with the leaves) Sassafras, Sassafras variifolium.

PAPAVERACEAE, the Poppy Family

Herbs with milky or colored juice, regular flowers, 2 sepals, 4, 6, or 8 petals, numerous stamens, and a 1-celled ovary.

1a. Leaves palmately lobed; flower 2.5-5 cm. wide, with 8 petals or more (leaf basal; flower white, in early spring) Bloodroot, Sanguinaria canadensis.

1b. Leaves pinnately toothed or lobed; flower 7-10 cm. wide, with 4-6 petals (4-8 cm. high; leaves clasping; summer) Poppy, Papaver somniferum.

1c. Leaves divided pinnately to the mid-rib into several toothed or lobed segments; flower 2.5 cm. broad or less (3-5 cm. high; flowers yellow) — 2.

2a. Flowers in clusters of 2-4, about 3 cm. wide (spring) Celandine Poppy, Stylophorum diphyllum.

2b. Flowers in umbels of 3-8, about 1.5 cm. wide Celandine, Chelidonium majus.

FUMARIACEAE, the Fumitory Family

Herbs with watery juice, compound or dissected leaves, and irregular flowers; sepals 2, small; petals 4, in two pairs, and one or both of the outer pair spurred at the base; stamens 6.

1a. Both outer petals spurred or sack-like at the base — 2.

1b. One outer petal spurred or sack-like at the base — 4.

2a. A climbing vine with flowers in panicles (white or pinkish flowers in summer) Climbing Fumitory, Adlumia fungosa.

2b. Low herbs (2-4 cm.) with basal leaves and white or pinkish flowers in racemes (early spring) — 3.

3a. Spurs of the corolla triangular, divergent Dutchman's Breeches, Dicentra cucullaria.

3b. Spurs of the corolla short and rounded Squirrel Corn, Dicentra canadensis.

4a. Flowers about 5 mm. long, pink-purple tipped with red (3-8 dm. high; summer) Fumitory, Fumaria officinalis.

4b. Flowers 10 mm. long or more, yellow, at least at the tip (2-6 dm. high) (Corydalis) — 5.

5a. Flowers yellow throughout (spring) Corydalis, Corydalis aurea.

5b. Flowers pink, tipped with yellow (summer). Corydalis, Corydalis sempervirens.

CRUCIFERAE, the Mustard Family

Herbs, with alternate, frequently lobed or dissected leaves, and regular flowers, usually in racemes; sepals and petals each 4, stamens 6, 4 long and 2 short (or rarely 2 only), ovary 1.

1a. Petals yellow or yellowish — 2.

1b. Petals white, pink, or purple, never yellow — 29.

2a. Leaves simple, entire or dentate, never lobed — 3.

2b. Leaves deeply lobed or compound (the bracteal leaves, at or near the flower-clusters, may be simple and unlobed) — 10.

3a. Leaves clasping the stem — 4.

3b. Leaves not clasping at base — 6.

4a. Clasping base and apex of leaf obtuse or rounded; pod very long and slender (3-8 dm. high; summer) Hare's Ear, Conringia orientalis.

4b. Clasping base and apex of leaf acute; pod obovoid (3-7 dm. high; early summer) (False Flax) — 5.

5a. Stem and leaves glabrous False Flax, Camelina sativa.

5b. Leaves and usually the stem pubescent False Flax, Camelina microcarpa.

6a. Flowers about 2 mm. wide (1-3 dm. high; flowers in summer) — 7.

6b. Flowers 5 mm. wide or more (2-6 dm. high; flowers in summer) — 8.

7a. Leaves about twice as long as broad, widest near or below the middle Whitlow Grass, Draba nemorosa.

7b. Leaves 3-5 times as long as broad, widest above the middle Yellow Alyssum, Alyssum alyssoides.

8a. Leaves lanceolate, gradually tapering to the base; flowers about 15 mm. wide Sand Rocket, Diplotaxis muralis.

8b. Leaves ovate, acute at base; flowers about 15 mm. wide — 22a.

8c. Leaves entire or minutely toothed; flowers 5-10 mm. wide — 9.

9a. Pods 25 mm. long or less, on slender pedicels about 8 mm. long Worm-seed Mustard, Erysimum cheiranthoides.

9b. Pods 20 mm. long or more, on stout pedicels about 4 mm. long Worm-seed Mustard, Erysimum parviflorum.

10a. Leaves bipinnate or dissected into very numerous divisions (3-8 dm. high; flowers in summer) — 11.

10b. Leaves simply pinnate — 13.

11a. Flowers about 5 mm. broad; pods about 20 mm. long by 1 mm. broad Herb Sophia, Sisymbrium sophia.

11b. Flowers about 3 mm. broad; pods about 8 mm. long by 2 mm. wide (Tansy Mustard) — 12.

12a. Stems gray with a close fine pubescence Tansy Mustard, Sisymbrium canescens.

12b. Stems green Tansy Mustard, Sisymbrium canescens var. brachycarpon.

13a. Pod short, not more than 3 times as long as wide (coarse plants, preferring wet or sandy ground; flowers in summer) (Yellow Cress) — 14.

13b. Pod elongated, more than 4 times as long as wide — 17.

14a. Stems creeping, with erect or ascending branches; flowers about 8 mm. wide Yellow Cress, Radicula sylvestris.

14b. Stems erect or ascending (3-10 dm. high); flowers about 4 mm. wide — 15.

15a. Pods about twice as long as the pedicels Yellow Cress, Radicula obtusa.

15b. Pods about as long as the pedicels, or shorter than them — 16.

16a. Plant glabrous or minutely pubescent Yellow Cress, Radicula palustris.

16b. Plant hirsute Yellow Cress, Radicula palustris var. hispida.

17a. Petals 7 mm. long or more; pod terminating in a conspicuous beak (coarse, weedy plants, 3-12 dm. high, blooming in summer) — 18.

17b. Petals of smaller size; pod not terminating in a conspicuous beak — 24.

18a. Upper stem-leaves clasping at the base Rutabaga, Brassica campestris.

18b. Upper stem-leaves not clasping — 19.

19a. Pod tipped with a slender cylindrical beak whose base is much narrower than the pod — 20.

19b. Pod gradually narrowed at its tip into a stout, flattened or angled beak — 22.

20a. Leaves oblanceolate, rather regularly pinnatifid, the terminal segment about the same size as the lateral ones Sand Rocket, Diplotaxis muralis.

20b. Leaves broad, irregularly pinnatifid especially below the middle, with a large terminal segment — 21.

21a. Beak of pod 3-4 mm. long Black Mustard, Brassica nigra.

21b. Beak of pod 5 mm. long or more Indian Mustard, Brassica juncea.

22a. Leaves dentate or lobed Charlock, Brassica arvensis.

22b. Leaves deeply pinnatifid — 23.

23a. Pod dehiscent when ripe by two valves, tipped with a flat or angled beak White Mustard, Brassica alba.

23b. Pod indehiscent, with spongy cross-partitions between the seeds, tipped with a conical beak Wild Radish, Raphanus raphanistrum.

24a. Terminal segment of the principal leaves much larger than the lateral segments; flowers in spring and summer — 25.

24b. Terminal segment of the principal leaves equaling or smaller than the lateral ones (5-10 dm. high; pods very long and slender; flowers in summer) Sisymbrium, Sisymbrium altissimum.

25a. Flowers about 3 mm. wide; pods erect and closely appressed to the stem (3-9 dm. high; weed blooming in summer) (Hedge Mustard) — 26.

25b. Flowers about 7 mm. wide; pods spreading or ascending (3-6 dm. high; flowers in spring) (Winter Cress) — 27.

26a. Pods pubescent Hedge Mustard, Sisymbrium officinale.

26b. Pods glabrous Hedge Mustard, Sisymbrium officinale var. leiocarpum.

27a. Lateral leaf-segments 5-8 pairs on the principal leaves Winter Cress, Barbarea verna.

27b. Lateral leaf-segments 1-4 pairs on the principal leaves — 28.

28a. Flowers bright yellow, in racemes; pods spreading or ascending Winter Cress, Barbarea vulgaris.

28b. Flowers pale yellow, in corymb-like clusters; pods erect and somewhat appressed Winter Cress, Barbarea stricta.

29a. Principal stem-leaves compound or deeply lobed (the uppermost or bracteal leaves may be simple) — 30.

29b. Principal stem-leaves entire, dentate, serrate, or sometimes shallowly lobed or none (the basal leaves, at the surface of the ground, may be deeply lobed or compound) — 42.

30a. Leaves ternately divided or compound (2-5 dm. high; flowers in spring) (Toothwort) — 31.

30b. Leaves pinnately divided or compound — 33.

31a. Leaf-segments lanceolate or narrowly oblong Toothwort, Dentaria laciniata.

31b. Leaf-segments ovate or ovate-oblong — 32.

32a. Stem-leaves 2, opposite or nearly opposite Toothwort, Dentaria diphylla.

32b. Stem-leaves 2-5, alternate Toothwort, Dentaria maxima.

33a. Plants growing in water, or in mud near water (spring and summer) — 34.

33b. Plants of dry or moist soil — 35.

34a. Aerial leaves distinctly compound, with 3-11 leaflets Water Cress, Radicula nasturtium-aquaticum.

34b. Aerial leaves merely serrate to pinnatifid; the submerged leaves, if present, dissected Lake Cress, Radicula aquatica.

35a. Flowers 5 mm. broad, or less — 36.

35b. Flowers 6 mm. broad, or more — 39.

36a. Stem-leaves irregularly pinnatifid or lobed; pod about as broad as long (2-4 dm. high; flowers in summer) Garden Cress, Lepidium sativum.

36b. Stem-leaves distinctly pinnatifid, with 3-6 pairs of lateral segments (spring) (Bitter Cress) — 37.

37a. Leaves chiefly basal, pubescent on the upper side (1-3 dm. tall) Bitter Cress, Cardamine hirsuta.

37b. Stem-leaves conspicuous, glabrous on the upper side — 38.

38a. Plant of dry soil; flowers about 3 mm. wide (1-4 dm. high) Bitter Cress, Cardamine parviflora.

38b. Plant of moist or wet soil; flowers about 5 mm. wide (2-8 dm. high) Bitter Cress, Cardamine pennsylvanica.

39a. Leaves irregularly pinnatifid or lobed, not segmented into definitely paired divisions (coarse plants 4-8 dm. high; flowers in summer) — 40.

39b. Leaves deeply segmented into 3-10 pairs of divisions — 41.

40a. Flowers pink or white from the first Radish, Raphanus sativus.

40b. Flowers yellow at first, turning white with age Wild Radish, Raphanus raphanistrum.

41a. Flowers pink or white, appearing in spring (2-5 dm. high) Cuckoo Flower, Cardamine pratensis.

41b. Flowers yellowish or cream-color; a weed blooming in summer (5-10 dm. high) Sisymbrium, Sisymbrium altissimum.

42a. A fleshy, much-branched plant of the shores of the Great Lakes, with a pod transversely divided into two joints (2-3 dm. high; summer) Sea Rocket, Cakile edentula.

42b. Pod not transversely divided into two joints — 43.

43a. Pod short, its length not more than 3 times its diameter — 44.

43b. Pod long and slender, its length more than 3 times its diameter — 55.

44a. Pods not conspicuously flattened, thick and plump, about circular in cross-section (flowers in summer) — 45.

44b. Pods distinctly flat — 46.

45a. A plant escaped from cultivation in dry or moist soil, with very large basal leaves (5-10 dm. high) Horse Radish, Radicula armoracia.

45b. A plant of water or very wet soil, the largest leaves seldom more than 15 cm. long (1-5 dm. tall) Lake Cress, Radicula aquatica.

46a. Stem-leaves clasping the stem by an auricled base — 47.

46b. Stem-leaves sessile or petioled, not clasping, or none — 49.

47a. Stem and leaves glabrous or pubescent; pod very flat and circular, about 10 mm. wide (1-5 dm. tall; early summer) Penny Cress, Thlaspi arvense.

47b. Stem and leaves glabrous or pubescent; pod not more than 5 mm. wide (1-6 dm. high; spring and early summer) — 48.

48a. Pods broadly ovate Field Cress, Lepidium campestre.

48b. Pods triangular, or slightly indented at the apex Shepherd's Purse, Capsella bursa-pastoris.

49a. Pods about circular, or a very little longer than broad — 50.

49b. Pods ovoid or oblong, broadest near the middle, and distinctly longer than wide (Whitlow Grass) — 53.

50a. Leaves entire (1-3 dm. high; flowers in summer) Yellow Alyssum, Alyssum alyssoides.

50b. Leaves serrate (2-6 dm. high; flowers in summer) — 51.

51a. Stamens 6 Garden Cress, Lepidium sativum.

51b. Stamens 2 (Pepper Grass) — 52.

52a. Petals present Pepper Grass, Lepidium virginicum.

52b. Petals none Pepper Grass, Lepidium apetalum.

53a. Petals deeply 2-cleft (about 1 dm. high; early spring) Whitlow Grass, Draba verna.

53b. Petals entire or barely notched at the tip — 54.

54a. Leaves all or chiefly at or near the base (about 1 dm. high; spring) Whitlow Grass, Draba caroliniana.

54b. Stems leafy up to the flowers (1-5 dm. high; summer) Whitlow Grass, Draba arabisans.

55a. Stem-leaves cordate or sagittate at the base and sessile, forming a more or less clasping leaf (3-10 dm. high) (Rock Cress) — 56.

55b. Stem-leaves sessile or somewhat petioled, but not clasping — 63.

56a. Seeds in 2 rows in each cavity of the pod (early summer) — 57.

56b. Seeds in 1 row in each cavity of the pod — 59.

57a. Calyx pubescent; the pods reflexed Rock Cress, Arabis holboellii.

57b. Calyx glabrous; the pods spreading or ascending — 58.

58a. Basal leaves densely pubescent Rock Cress, Arabis brachycarpa.

58b. Basal leaves smooth or nearly so Rock Cress, Arabis drummondii.

59a. Petals conspicuous, about twice as long as the calyx, or longer; straight, erect, mostly unbranched plants — 60.

59b. Petals inconspicuous, equaling or but little longer than the calyx — 61.

60a. Pods 3-4 cm. long, ascending (summer) Rock Cress, Arabis patens.

60b. Pods 8-10 cm. long, recurved (late spring) Rock Cress, Arabis laevigata.

61a. Pods widely spreading; stem usually sparingly branched near the base (spring) Rock Cress, Arabis dentata.

61b. Pods erect or appressed; stem usually unbranched (summer) — 62.

62a. Stem-leaves and stem smooth and glaucous Rock Cress, Arabis glabra.

62b. Stem-leaves and stem almost always pubescent, and never glaucous Rock Cress, Arabis hirsuta.

63a. Principal stem-leaves 7-10 cm. long, or more — 64.

63b. Principal stem-leaves 2-5 cm. long — 65.

64a. Leaves lanceolate or oblong; flowers 10 mm. wide or less (3-7 dm. high; summer) Rock Cress, Arabis canadensis.

64b. Leaves ovate or ovate-lanceolate; flowers 15-20 mm. wide (5-8 dm. high; late spring and summer) Dame's Rocket, Hesperis matronalis.

65a. Basal leaves ovate to orbicular or cordate, not more than twice as long as broad (1-3 dm. high; spring) (Bitter Cress) — 66.

65b. Basal leaves oblong, lanceolate, or oblanceolate, at least 3 times as long as broad (1-3 dm. high) — 67.

66a. Flowers purple or rose color Bitter Cress, Cardamine douglassii.

66b. Flowers white Bitter Cress, Cardamine bulbosa.

67a. Basal leaves pinnatifid (spring and summer) Rock Cress, Arabis lyrata.

67b. Basal leaves entire or toothed — 68.

68a. Leaves narrowly oblanceolate; rare plant occurring from Mackinac northward (summer) Rock Cress, Braya humilis.

68b. Leaves obovate or oblong; an introduced weed (spring) Mouse-ear Cress, Sisymbrium thalianum.

CAPPARIDACEAE, the Caper Family

Herbs, with alternate compound leaves, 4 petals, and 6 or more stamens, which are about equal in length; fruit a 1-celled pod.

One species in Michigan, stamens about 11; leaflets 3 (2-4 dm. high; flowers yellowish, in summer) Clammy-weed, Polanisia graveolens.

RESEDACEAE, the Mignonette Family

Herbs, with alternate leaves and terminal racemes of small yellowish flowers; sepals 6, petals 6, stamens numerous.

One species in Michigan, with divided leaves and irregularly cleft petals, blooming in summer Yellow Mignonette, Reseda lutea.

SARRACENIACEAE, the Pitcher Plant Family

Insectivorous plants, with hollow, pitcher-shaped leaves, and large purple flowers at the ends of naked stems.

One species in Michigan, growing in bogs and blooming in late spring Pitcher Plant, Sarracenia purpurea.

DROSERACEAE, the Sundew Family

Insectivorous herbs, with a rosette of basal leaves bearing gland-tipped bristles on their upper surface, and with slender racemes of small white flowers in summer; inhabitants of bogs and swamps (2 dm. high, or less).

1a. Leaf-blade about as long as wide Sundew, Drosera rotundifolia.

1b. Leaf-blade about 2-3 times as long as wide Sundew, Drosera longifolia.

1c. Leaf-blade about 5-8 times as long as wide Sundew, Drosera anglica.

1d. Leaf-blade narrowly linear, about 10 times as long as wide Sundew, Drosera linearis.

PODOSTEMACEAE, the River Weed Family

Small submerged aquatics, growing attached to stones in running water, with dissected leaves and minute flowers.

One species in Michigan River Weed, Podostemum ceratophyllum.

CRASSULACEAE, the Orpine Family

Herbs, with usually alternate leaves; the sepals, petals, and pistils each 4 or 5, or in one species the petals none, and the stamens as many or twice as many as the sepals.

1a. Leaves entire (Stonecrop) — 2.

1b. Leaves toothed — 3.

2a. Leaves 3-5 mm. long, very thick and fleshy (tufted plants about 1 dm. high, with yellow flowers in summer) Stonecrop, Sedum acre.

2b. Leaves 10-30 mm. long, flat (tufted plants 1-2 dm. high; flowers white, in spring) Stonecrop, Sedum ternatum.

3a. Petals present, purple (2-5 dm. high; summer) Live-for-ever, Sedum purpureum.

3b. Petals none (3-6 dm. high; summer) Ditch Stonecrop, Penthorum sedoides.

SAXIFRAGACEAE, the Saxifrage Family

Herbs or shrubs, with alternate or opposite leaves; petals and sepals each 5, or the petals none; stamens 5 or 10; styles or stigmas 2-4.

1a. Shrubs with lobed leaves (3-15 dm. high; flowers in late spring) — 2.

1b. Herbs — 12.

2a. Stems thorny — 3.

2b. Stems not thorny (Currant) — 8.

3a. Flowers and fruits in racemes Swamp Currant, Ribes lacustre.

3b. Flowers and fruit in short clusters (Gooseberry) — 4.

4a. Ovary and fruit prickly and bristly Gooseberry, Ribes cynosbati.

4b. Ovary and fruit smooth, or sometimes a little glandular — 5.

5a. Stamens equaling the ovate calyx-lobes in length, or a very little longer — 6.

5b. Stamens distinctly longer than the linear calyx-lobes — 7.

6a. Leaves glabrous beneath, or nearly so Gooseberry, Ribes oxyacanthoides.

6b. Leaves softly pubescent beneath Gooseberry, Ribes oxyacanthoides var. calcicola.

7a. Flowers, including the stamens, about 15 mm. long Gooseberry, Ribes gracile.

7b. Flowers, including the stamens, about 8 mm. long Gooseberry, Ribes rotundifolium.

8a. Calyx prolonged above the ovary into a tube which is longer than the sepals — 9.

8b. Calyx-tube shorter than the ovary or none — 10.

9a. Flowers greenish-yellow, inconspicuous; calyx-tube narrowly bell-shape Black Currant, Ribes floridum.

9b. Flowers bright yellow, conspicuous; calyx-tube narrow, with spreading lobes Golden Currant, Ribes aureum.

10a. Ovary and berry bristly with glandular hairs Skunk Currant, Ribes prostratum.

10b. Ovary and fruit smooth, or with sessile glands — 11.

11a. Leaves dotted beneath with resinous glands Black Currant, Ribes hudsonianum.

11b. Leaves glabrous or pubescent beneath, without resinous glands Red Currant, Ribes triste.

12a. Flowers minute, yellowish, without petals, in the axils of the leaves (1-2 dm. high; flowers in spring) Golden Saxifrage, Chrysosplenium americanum.

12b. Flowers large, solitary, terminating erect stalks (leaves mostly basal; flowers white, in late summer; flower-stalks 1-5 dm. high) (Grass-of-Parnassus) — 13.

12c. Flowers in terminal racemes, panicles, or clusters — 15.

13a. Flowers less than 2 cm. wide; leaves narrowed to the base Grass-of-Parnassus, Parnassia parviflora.

13b. Flowers 2-3.5 cm. wide; leaves rounded or cordate at the base — 14.

14a. A 3-cleft scale at the base of each petal Grass-of-Parnassus, Parnassia caroliniana.

14b. A many-cleft (9-15) scale at the base of each petal Grass-of-Parnassus, Parnassia palustris.

15a. Leaves linear to oblanceolate, 3 times as long as broad, or more, and pinnately veined (Saxifrage) — 16.

15b. Leaves broadly ovate to nearly circular, frequently cordate at the base, and always palmately veined or lobed — 20.

16a. Leaves basal; the flower-stalk bearing no leaves except small ones at the base of its branches — 17.

16b. Flower-stalk leafy below (1-3 dm. high; flowers yellow, summer) — 18.

17a. Petals white; sepals erect; leaves conspicuously toothed, 3-10 cm. long (1-3 dm. high; spring) Saxifrage, Saxifraga virginiensis.

17b. Petals greenish; sepals reflexed; leaves minutely toothed or entire, 10-30 cm. long (5-10 dm. high; spring) Saxifrage, Saxifraga pennsylvanica.

18a. Leaves with 3 sharp teeth at the apex Saxifrage, Saxifraga tricuspidata.

18b. Leaves with numerous teeth or entire — 19.

19a. Leaves linear, chiefly on the stem Saxifrage, Saxifraga aizoides.

19b. Leaves spatulate, chiefly in a basal rosette Saxifrage, Saxifraga aizoon.

20a. Stamens 5 (leaves mostly basal; flowers greenish or purplish in late spring, on stalks 5-10 dm. high) (Alum Root) — 21.

20b. Stamens 10 (flowers white, in spring) — 23.

21a. Flowers regular Alum Root, Heuchera americana.

21b. Flowers irregular, the calyx oblique, longer on the upper side than on the lower — 22.

22a. Stamens projecting beyond the calyx Alum Root, Heuchera hirsuticaulis.

22b. Stamens not projecting beyond the calyx Alum Root, Heuchera hispida.

23a. Stem-leaves alternate or none — 24.

23b. Stem with a pair of opposite leaves (2-4 dm. high) Bishop's Cap, Mitella diphylla.

24a. Petals deeply fringed (1-2 dm. high) Bishop's Cap, Mitella nuda.

24b. Petals entire (1-3 dm. high) False Mitrewort, Tiarella cordifolia.

HAMAMELIDACEAE, the Witch Hazel Family

Shrubs, with alternate simple leaves; sepals, petals, and stamens each 4; ovary 2-lobed.

One species in Michigan; tall shrub with obovate leaves and yellow flowers appearing late in autumn Witch Hazel, Hamamelis virginiana.

PLATANACEAE, the Plane Tree Family

Trees, with broad, palmately veined and lobed leaves, and minute flowers in dense spherical heads.

One species in Michigan Sycamore, Platanus occidentalis.

ROSACEAE, the Rose Family

Trees, herbs, or shrubs, with alternate, frequently compound leaves; petals and sepals usually 5, stamens numerous, pistils 1 to many; receptacle expanded into a saucer-shape or cup-shape organ, bearing the sepals, petals, and stamens at its margin, the pistils at its center, and resembling a calyx-tube or flattened calyx.

1a. Shrubs or trees — 2.

1b. Herbaceous plants — 48.

2a. Leaves compound — 3.

2b. Leaves simple — 24.

3a. Flowers in large panicles or corymbs, each flower 5-10 mm. across; leaflets 7 or more — 4.

3b. Flowers solitary or in small clusters, each flower usually 20-80 mm. wide; leaflets frequently only 3 or 5 — 7.

4a. Flowers in a pyramidal or oblong panicle, the ovaries superior (1-2 m. high; flowers white, in summer) — 70b.

4b. Flowers in rounded or hemispheric clusters, the ovary inferior — 5.

5a. Leaves pubescent on the lower surface Rowan Tree, Pyrus aucuparia.

5b. Leaves glabrous beneath when mature (small trees; flowers white, in early summer or late spring) (Mountain Ash) — 6.

6a. Leaves acuminate at the apex Mountain Ash, Pyrus americana.

6b. Leaves obtuse or acute at the apex Mountain Ash, Pyrus sitchensis.

7a. Flowers yellow (5-10 dm. high; summer) Cinquefoil, Potentilla fruticosa.

7b. Flowers pink or red, rarely white, 4-10 cm. across (shrubs, 5-15 dm. high, or climbing; stems usually thorny; flowers in early summer) (Rose) — 8.

7c. Flowers white, 1-3 cm. across (4-20 dm. high; flowers in late spring) — 16.

8a. Leaflets on most of the leaves 3; styles cohering in a column which protrudes from among the stamens Climbing Rose, Rosa setigera.

8b. Leaflets 5-11; styles not cohering in a protruding column — 9.

9a. Sepals persistent on the fruit after flowering — 10.

9b. Sepals soon deciduous from the young fruit after flowering — 14.

10a. A pair of spines below each leaf larger than the other spines — 11.

10b. Spines all alike in size or nearly so, or absent completely — 12.

11a. Sepals entire Wild Rose, Rosa woodsii.

11b. Sepals pinnatifid Dog Rose, Rosa canina.

12a. Stems with few thorns or none at all Wild Rose, Rosa blanda.

12b. Stems prickly — 13.

13a. Fruit somewhat pear-shape, narrowed toward the base. Wild Rose, Rosa acicularis.

13b. Fruit globose, rounded at the base Wild Rose, Rosa acicularis var. bourgeauiana.

14a. The pair of spines at the base of each leaf straight or nearly so Wild Rose, Rosa humilis.

14b. The pair of spines at the base of each leaf distinctly recurved or hooked — 15.

15a. Leaves densely glandular-pubescent beneath Sweetbrier, Rosa rubiginosa.

15b. Leaves glabrous or minutely pubescent Swamp Rose, Rosa carolina.

16a. Stems trailing or creeping — 17.

16b. Stems erect, ascending, or arched — 19.

17a. Stems distinctly shrubby and thorny (Dewberry) — 18.

17b. Stems almost herbaceous, without thorns Dwarf Raspberry, Rubus triflorus.

18a. Leaves thin, dull above; fruit black, large and juicy Dewberry, Rubus villosus.