Distinguishing characteristics: Narrow leaves, whitish color of branches, minutely tuberculate seeds. Notes: Holmes states that the plants in Somalia may represent a different taxon rom those in the type locality in the Red Sea Hills (Sudan).
S. Holmes (1993) 1:306-337
Plants rounded, densely branched shrubs 0.5-4 m tall, occasionally scambling and becoming 5 m tall;branches succulent, 5-10 mm thick, marked with very proment, dark broan callose leaf scars. Leaves sessile, without stipules; blades linear-lanceolate, 1-1.5 cm long. 0.3-0.5 cm wide, very quickly deciduous. Cymes in terminal 5-7-branched umbels, outer cymes on rays 1-2 cm long, surrounding a central, sessile, usually staminate, cyathium; bracts ovate, about 3.5 mm long and 3 mm wide. Cyathia subsessile, 7-8 mm in diameter, the central cyathium larges; glands 4 or 6-8 on the central cyathium, separate, 3-3.5 mm wide, yellow; stamens well exserted; ovaries glabrous; styles about 3 mm long, united at the base, spreading distally, with thickened, bifid tips. Capsules exerted on clightly recurved pedicels, 7-8 mm long, very obtusely 3-lobed, 3-8 mm long, 9-10 mm in diameter, buff tinged with pink; seeds ovoid, about 3 mm long, 2.75 mm wide, smooth, greyish brown. caruncles about 1mm across.
Euphorbia numbica grows on alluvial limeston soils win open Acacai bushland and in Buxus scrub on north-facing, mist-covered limestone scarp at 365-1770 m. It is know from region N1 in the Flora of Somalia and from Sudan, Ethiopia, and northernn Kenya.