Euphorbia pentagona Royle
A dense-crowned succulent-branched spiny, glabrous, readily-deciduous shrub or small tree usually up to 5 m tall, less often to 8 m, and 2 m in girth. Wood white, soft, spongy. Branches 5-7-angled, c. 5 cm thick, with broad flat faces between the angles, and the angles produced into straight undulate wings or ridges with a pair of stipular spines at the crest of each undulation. Leaves alternate, sessile or subsessile. Leaf-blades oblanceolate-spathulate, 5-15 x 1-4 cm, subacute or obtuse and mucronate at the apex, gradually tapering to the base, entire, lateral nerves 8-10 pairs, obscure, thick, fleshy. Stipules spiny, 3-5 mm long, paired on each spine-shield. Cyathia in sessile ‘cymes’ of 3 each, arising from the internodal sinuses, yellowish. Glands transversely oblong, ochreous. Fruits triradiate, the lobes somewhat compressed, l x 1.5 cm, smooth, glabrous, greyish-green.
Fl.: ‘in the hot weather’ (Parker).
Type: The illustration of Euphorbia pentagona Royle (Ill. Bot. Himal. t. 82, f. 1. May, 1836, based on material from the Suen Range, India.
Distribution: N. India (Himalayan foothills). Common on hot, dry rocky slopes; c. 1500'/450 m - 6000'/1830 m. Cultivated as a hedge-plant in the plains.