Plate 88. DICOMA zeyheri.

Transvaal. Zululand.

Compositae. Tribe Mutisieae. Dicoma, Cass.; Benth. et Hook. f. Gen. Plant. vol. ii. p. 492.

Dicoma Zeyheri, Cass. in Linn. vol. xxiii. p. 71; Fl. Cap. vol. iii. p. 518.

The genus Dicoma comprises a small group of half-woody shrubs with acuminate usually pungent involucral-bracts. About twenty-five species are known, most of which are found in Tropical and South Africa, one extending into Western India. There is also a peculiar species, D. cana, in the island of Socotra. The tribe Mutisieae, to which Dicoma belongs, is but sparingly represented in Africa and has its head-quarters in South America.

Our present plant is common in parts of the Transvaal Highveld, and is found in flower from January to March. It has also been collected at Barberton by Mr. E. E. Galpin. Like so many of the shrubby plants occurring in the grass-veld, it has deep underground roots from which the stems arise, but, unlike the majority of them, is one of the last to flower.

The specimen from which this plate was prepared was collected by Miss S. Gower near the Botanical Laboratories, Pretoria. Specimens are preserved in the National Herbarium, Pretoria (No. 2581).

Description:—A somewhat woody undershrub about 30 cm. high with deep underground roots. Stems striate, cobwebby. Leaves 5·5-7 cm. long, 1-1·7 cm. broad, lanceolate, acute, or obtuse, sometimes subacuminate, slightly broadened and half-clasping at the base, usually entire, more rarely minutely and remotely toothed, glabrous above, cobwebby beneath. Capitulum shortly peduncled, about 5 cm. in diameter when expanded. Involucral-bracts in about 8 rows, the outermost strongly reflexed, the rest erect spreading, 1·5-2·5 cm. long, 4-9 mm. broad, ovate, acuminate, pungent, with membranous margins (except the outermost); the innermost bracts erect, closely enveloping the flowers, almost wholly membranous. Involucre 1·5 cm. in diameter, slightly convex, deeply honeycombed. Flowers all hermaphrodite. Corolla-tube 6 mm. long, cylindric for 5 mm. then suddenly campanulate, glabrous; lobes 4·5 mm. long, linear, gradually tapering upwards, obtuse, recurved in open flowers. Stamens inserted at the widened portion of the corolla-tube; filaments 1·5 mm. long, linear; anthers 7·5 mm. long, linear, lanceolate, acute at the apex, long-tailed at the base; tails hairy with ascending hairs. Ovary densely villous; style 1·5 cm. long, cylindric, glabrous; lobes 0·5 mm. long, ovate, obtuse, convex and hairy on outer side. Pappus 9 mm. long, dense and completely hiding the corolla-tube; setae long, plumose.

Plate 88.—Fig. 1, longitudinal section of head; Fig. 2, surface view of part of receptacle; Fig. 3, involucral-bract; Fig. 4, an inner involucral-bract; Fig. 5, disc-floret before style appears; Fig. 6, disc-floret with style through the stamens; Fig. 7, disc-floret with pappus removed; Fig. 8, stamen; Fig. 9, apex of style; Fig. 10, a single pappus bristle; Fig. 11, portion of a leaf showing the minute teeth on the margin.

F.P.S.A., 1923.

K A Lansdell del