Plate 87. CERATOTHECA triloba. Bechuanaland, Cape Province, Natal, Transvaal.

Pedallaceae. Tribe Sesameae. Ceratotheca, Endl.; Benth. et Hook. f. Gen. Plant. vol. ii. p. 1059. Ceratotheca triloba, E. Mey. ex Bernh. in Linnaea, vol. xvi. 29; Fl. Cap. vol. iv. sect. ii. p. 462.

The genus Ceratotheca, of which there are five species known, is confined to Africa, but the species figured in the accompanying plate is the only one recorded in South Africa. The genus is closely related to Sesamum, only differing by the capsule having two divergent horns or spines at the apex instead of being acute or beaked as in the latter genus. The species was first described in 1842 under the name Sporledera triloba, but, as pointed out in the Botanical Magazine under Tab. 6974, there is no justification for establishing a genus to include this species separate from Ceratotheca. The oldest record from South Africa appears to be specimens collected by Drège between the Umtata and St. John’s River, but since then it has been found by numerous collectors. When fresh, the leaves have a very objectionable odour. The plant is very common during January on the hills at Wonderboom, near Pretoria. Our specimen was collected by Dr. R. Reitz. Specimens are preserved in the National Herbarium, Pretoria (No. 1605).

Description:—An herbaceous plant with erect stems, sometimes 6 ft. high, simple or branched. Stems obtusely 4-angled, glandular-pilose. Leaves opposite, sometimes alternate, petiolate; petioles 0·5-5 cm. long, grooved above, convex beneath, glandular-pilose; lamina 2-6·5 cm. long, ovate, more or less 3-lobed with the lobes crenate (the uppermost leaves not lobed), cordate at the base, palmately veined, with the veins prominent beneath, depressed above, glandular-pubescent. Flowers solitary, axillary, with often two abortive flowers in the same leaf-axil. Pedicels 5 mm. long, terete, glandular-pilose. Calyx divided almost to the base; the lobes erect, 0·8-1 cm. long, lanceolate, acuminate, sub-obtuse, glandular-pilose; the anterior lobe the smallest. Corolla-tube 3·5 cm. long, ventricose at the base, then slightly constricted and widening into a broad campanulate portion 1·4 cm. diameter, glandular-pilose; lobes 0·8 cm. long, about 1 cm. broad, transversely oblong, rounded above; the posterior lobe longer. Stamens of two different lengths, inserted above the ventricose portion of the corolla-tube; filaments 0·9-1·3 cm. long, glabrous; anthers 5 mm. long, linear. Ovary 6 mm. long, oblong in outline, densely villous, with 2 divergent horns at the apex; style 1·8 cm. long, terete, glabrous; stigmas recurved, papillose. Fruit 2 cm. long, oblong, with 2 divergent horns, glandular-pilose.

Plate 87.—Fig. 1, portion of flowering branch; Fig. 2, corolla laid open; Fig. 3, pistil; Fig. 4, cross-section of ovary; Fig. 5, stigmas; Fig. 6, stamens and anther; Fig. 7, fruits; Fig. 8, fruit dehisced; Fig. 9, leaf; Figs. 10, 11, abortive flowers.

F.P.S.A., 1923.

S. Gower del.