Plate 197.

EUPHORBIA TRIDENTATA. Cape Province. Euphorbiaceae. Tribe Euphorbieae. Euphorbia, Linn.; Benth. et Hook. f. Gen. Plant. vol. iii. p. 258.

Euphorbia tridentata, Lam. Encycl. ii. 416; Fl. Cap. vol. v. sect. ii. p. 298.

The species of Euphorbia figured on the accompanying Plate is a somewhat rare plant and until quite recently it was not known where the plant was found, although it was known in European gardens and figured almost 100 years ago. The plant belongs to a small group of three species in the genus characterised by having the branches constricted at their origin of growth. All of them are very dwarf plants.

We are indebted to Mr. H. M. Bartlett of Riversdale for the specimens which he sent in July 1924, and these were successfully grown at the Division of Botany, Pretoria, and flowered in September 1925.

Description:—Plant dwarf, succulent, spineless, branching from the base. Branches ascending or somewhat spreading, 2·5 to 15 cm. long, 1 to 1·4 cm. thick, cylindric or slightly tapering upwards, tessellately tuberculate with hexagonal flattish tubercles 6 to 10 mm. in diam., having a slightly prominent whitish leaf-scar, glabrous, dull green. Leaves sessile, soon deciduous, 4 to 6 mm. long, 3 to 4 mm. broad, elliptic or elliptic-oblong, acute, dark green, with a reddish minutely toothed margin. Peduncles 3 to 4 at the ends of the branches, about 4 mm. long, bearing a pair of ovate or elliptic bracts and 1 involucre, glabrous. Involucre about 1·3 to 1·8 cm. in diam., cup-shaped, glabrous, with 5 glands and 5 transversely oblong, toothed and ciliate, inflexed, purplish lobes. Glands subcontiguous, about 5 mm. in diam. across the tips, very concave at the basal part, divided into 3 to 4 spreading finger-like corrugated white processes 2 to 3 mm. long. Ovary pedicellate, scarcely exserted, with styles 7 mm. long, united for two-thirds of their length, with entire spreading tips. (National Herb., Pretoria, No. 2989.)

Plate 197.—Fig. 1, inflorescence; Fig. 2, gland with lobes.

F.P.S.A., 1925.