Transvaal. Cape Province.
Apocynaceae. Tribe Echitideae.
Adenium, Roem. et Schult.; Benth. et Hook. f. Gen. Plant. vol. ii. p. 722.
Adenium oleifolium, Stapf, var. angustifolium, Phillips var. nov., a
typo foliis angustis differt.
The genus Adenium is represented in South Africa by three species found in the Transvaal, Swaziland and the North-Western Cape Province. Species of the genus are also found extending through tropical Africa to Socotra. On Plate 16 we figured Adenium multiflorum, from which the present plant differs in having long narrow leaves; both, however, have very large tuberous underground stems from which the branches arise. The peculiar tailed anthers and the scales in the corolla-throat which sometimes form small pouches are characteristic of the genus.
Specimens were submitted to Kew for confirmation of the name, and the Director reports “very probably A. oleifolium, Stapf, but leaves are much narrower than in the type,” and it was thought advisable to describe this as a narrow-leaved variety.
Our plate was prepared from specimens collected by Dr. W. M. Borcherds at Upington, and forwarded by him to the Division of Botany, Pretoria.
Description:—Plant with large underground tuberous stems from which the branches arise. Branches densely pubescent when young, at length becoming glabrous. Leaves crowded at the ends of the branches, 6-10 cm. long, 2-4 mm. broad, linear, acute, pubescent. Flowers terminal. Sepals 6·5 mm. long, ovate, acuminate, acute, densely pilose, united at the base. Corolla-tube 3·5 cm. long, cylindric and 3 mm. in diameter in lowest third, campanulate and 1·1 cm. in diameter in uppermost ⅔, pubescent without and within and with pockets in the angles formed by the lobes; lobes 1·3 cm. long, 8-9 mm. broad, broadly-elliptic, acuminate, sub-acute, minutely ciliate. Filaments 4 mm. long, thick, terete, densely pilose; anthers 4 mm. long, hairy on the backs, sagittate at the base and produced into a long coiled apical hairy appendage 1 cm. long. Ovary 2 mm. long, 2 mm. broad, glabrous, separating into 2 carpels; style 1·6 cm. long, cylindric, glabrous; stigmas 3 mm. long, lanceolate, subacuminate, with a mass of glandular hairs at the back which fix the stigmas to the connective of the anthers. (National Herb. Pretoria, No. 2598.)
[Plate 105.]—Fig. 1, plant reduced; 2, corolla laid open; 3, corolla from above; 4, pocket in corolla; 5, calyx; 6, stamens; 7, style and stigma; 8, carpels; 9, median longitudinal section of flower.