ARTIFICIAL KEY TO THE FAMILIES OF MONOCOTYLEDONES REPRESENTED IN THIS FLORA.
Reading edition
a) Flowers very small, arranged on a spadix, more or less enclosed by a green or coloured spathe; erect, creeping or climbing herbs; rootstock often tuberous or thick and fleshy.
Araceæ
aa) Flowers not arranged as above:
b) Small or minute floating plants not differentiated into stem and leaves and with much reduced flowers consisting of 1-2 stamens and a sessile ovary either naked or enclosed in a membranous perianth, anthers 1-2 celled; ovary 1-celled; ovule 1 or more on a basal placenta.
Lemnaceæ
bb) Characters not as above; if aquatic plants then usually with well-developed leaves:
c) Ovary apocarpous, of more than 1 carpel:
d) Submerged aquatic plants:
e) Perianth-segments 1-3, white or coloured.
Aponogetonaceæ
ee) Perianth-segments 4 and herbaceous, or absent.
Potamogetonaceæ
dd) Not aquatic or if so then not submerged:
e) Carpels indehiscent; ovules 1 to few, basal or on the inner angle of the carpel; marsh or aquatic herbs.
Alismataceæ
ee) Carpels dehiscent; ovules numerous on reticulately branched parietal placentas; scapigerous marsh herbs with milky juice; stamens usually 9.
Butomaceæ
eee) Carpels or fruit indehiscent, trees or shrubs with simple stems and usually large, often palmate leaves.
Palmaceæ (part)
cc) Ovary syncarpous or carpel solitary:
d) Ovary superior:
e) Flowers in the axils of membranous or more or less dry bracts (glumes) arranged in spikelets mostly arranged in spikes, racemes, panicles or heads; carpel solitary; perianth of small scales or bristles or absent:
f) Stems usually triangular, solid and without nodes; leaf-sheaths mostly closed all round the stem and usually without a ligule; filament often attached to the base of the anther; ovule basal; seed free from the pericarp.
Cyperaceæ
ff) Stems mostly cylindrical and hollow between the nodes; leaf-sheaths nearly always split down one side and often terminating in a distinct ligule; filament usually attached to the back of the anther; ovule attached laterally; seed more or less adnate to the pericarp.
Gramineæ
ee) Flowers usually with a distinct perianth or at any rate not in spikelets, etc., as above; ovary usually composed of more than 1 carpel:
f) Flowers mostly hermaphrodite or if unisexual then not collected into involucrate heads or dense spikes:
g) Ovules on parietal placentas; fertile stamens 3: all the perianth-segments petaloid; aquatic herbs; stamens 3 or 1.
Pontederiaceæ (part)
gg) Ovules on axile or basal placentas; fertile stamens usually 6:
h) Perianth present:
i) Perianth-segments 2-seriate, the outer herbaceous, the inner petaloid; leaf-bases sheathing.
Commelinaceæ
ii) Perianth-segments all more or less petaloid:
j) Aquatic floating herbs with long petioles sheathing at the base; 3 upper stamens included, 3 lower ones more or less exserted.
Pontederiaceæ
jj) Not aquatic or rarely subaquatic; stamens 6, more or less equal;
Liliaceæ
hh) Perianth absent or very rudimentary; carpel 1; submerged aquatics with branched filiform smooth or muricate stems, flowers diœcious or monœcious, axillary, small.
Naiadaceæ
ff) Flowers unisexual, collected into involucrate heads or dense spikes:
g) Flowers in dense involucrate heads; low herbs often stemless with mostly densely crowded leaves.
Eriocaulaceæ
gg) Flowers in spadices; trees or shrubs, the stems bearing thick aerial roots.
Pandanaceæ
ggg) Flowers in dense cylindric spikes; aquatic herbs with linear alternate leaves and creeping rhizomes.
Typhaceæ
dd) Ovary inferior:
e) Stamens 3-6:
f) Ovules parietal:
g) Leaves not divided; stigma not umbrella-shaped, flowers hermaphrodite or unisexual.
Hydrocharitaceæ
gg) Leaves divided; stigma umbrella-shaped; leaves large, divided.
Taccaceæ
ff) Ovules axile, basal or apical:
g) Perianth-lobes or segments 3-6:
h) Stamens 6 or 3; flowers very small, diœcious; stems climbing.
Dioscoreaceæ
hh) Stamens 6; flowers conspicuous, hermaphrodite; stems not climbing.
Amaryllidaceæ
hhh) Stamens 3; inserted opposite the outer perianth-segments; not climbing.
Iridaceæ
gg) Perianth-segment 1; stamens 5, rarely 6; leaves with pinnate nervation; tall plants.
Musaceæ
ee) Stamen 1:
f) Flowers actinomorphic or nearly so:
g) Anthers 2-celled; ovules numerous; perianth-segments united below.
Zingiberaceæ
gg) Anthers 1-celled; ovules solitary in each cell; petiole thickened towards the apex.
Marantaceæ
ff) Flowers very zygomorphic; ovules numerous; andrœcium united with the gynæcium into a column; anther sessile or subsessile on the column.
Orchidaceæ