Plate 113.
ADENIA digitata.
Transvaal.
Passifloraceae. Tribe Modecceae.
Adenia, Forsk. Fl. Aegypt. Arab. 77 (1775).
Adenia digitata, Engl. Bot. Jahrb. vol. xiv. p. 375; Modecca digitata,
Harv. Thes. Cap. t. 12, 167; Fl. Cap. vol. ii. p. 499.
The species of Adenia described below and figured on the accompanying Plate is of special interest, inasmuch as the large tuberous roots have proved to be extremely poisonous. In October 1922 the plant was brought to the notice of the Division of Botany by Dr. H. Osborne of Pretoria, who reported that two white labourers were admitted to the Pretoria Hospital suspected of having been poisoned by eating a portion of the root, and that one of them died shortly after admission to the Hospital. A sample of the root sent in by Dr. Osborne was submitted to Drs. H. H. Green and W. H. Andrews of the Division of Veterinary Research, and as a result of their investigations two types of poison were discovered. One of these acts very rapidly, and with symptoms which can be attributed to the small amount of a cyanogetic glucoside; the other acts more slowly, but its chemical nature is as yet unknown. A full account of these investigations will be published in the Report of the Director of Veterinary Research.
The fruits of Adenia digitata are berries of a very attractive nature, and also appear to be poisonous, for some years ago in the Pretoria District two native children died after eating them.
The plant is quite common in the Pretoria District, and also occurs in the Barberton District. It has long, graceful branches provided with tendrils, by means of which it climbs up neighbouring bushes and shrubs.
Description:—Roots tuberous, sometimes up to 50 cm. in diameter. Stems striate. Leaves 8 to 14 cm. long, digitately 3-to 5-lobed; the middle lobe pinnatisect; the side lobes again lobed on one side only or pinnatilobed, more rarely almost entire; the mid-rib prominent above and beneath, and with two prominent glands on the upper side at base of the lamina, and with glands beneath at the base of each leaf-segment, glabrous; petiole 1·3 to 1·7 cm. long, 6 to 7 mm. broad, flat above, convex beneath, glabrous. Calyx-tube 1·5 cm. long, campanulate, 1 cm. in diameter above, narrowing to 1·5 mm. in diameter at the base, glabrous; lobes 7 cm. long, 5·5 mm. broad, ovate, obtuse, glabrous; two lobes with entire, the other three with lacerated margins. Petals 9 mm. long, 2·5 mm. broad at the widest part, obovate, acuminate, obtuse, narrowed at the base, with shortly ciliated margins, 3-nerved. Filaments united at the base, 4 mm. long, linear, broadening at the base; anthers 6·5 mm. long, 1·5 mm. broad, linear, falcate when seen in side view. Glands at base of filaments ·5 mm. long, more or less quadrate. Style 1 mm. long, bilobed at the apex. Corona represented by a fimbriated rim. Fruit fleshy, 3·5 cm. long, 2·5 cm. in diameter. Female flower not seen. (National Herb. Pretoria, No. 2639.)