Habitat: Arid hillsides on limestone substrates, 600-1800 elevation.
Succulent shrubs up to 130 cm tall, multicaule, forming cushions of 0.5-2 m diam. Stems branched or not, glabrous, green glaucous to glaucescent, 4-angled rarely 3-angled, 2-3 cm thick, facets more or less concave; spine-shields ovate, no decurrent; spines short, 2-10 mm, attached basally to the spine-shield; flowering eye not contiguous with the spine shield. Leaves opposite, minute, on young growth, soon deciduous. Cyathia arranged in axillary cymes, 3 per cyme; lateral cyathia hermaphrodite, peduncles thick; central cyathium male, subsessile, developing first and falling off before the maturity of the capsules of the two other cyathia; subcyathial leaves 2, ovate-triangular, membranaceous. Involucre 3-5 mm long, campanulate, glabrous; lobes 5-6 subsemi-orbicular, membranaceous, obtuse, margin lacerate-cilliate; glands 5-6, fleshy, yellowish, 3-5 mm long, elliptic or trapezoidal. Staminate flowers: pedicel cylindrical surpasing the involucre at maturity, glabrous; bracts glabrous, enlongated and laciniate-fimbriate distally; filaments longer than anthers. Pistillate flower: ovary glabrous; styles 1.2-2 mm long, united at base, equaling about one-third of the length of the capsule, sub-bifid. Capsule depressed, 4-5 x 6-7 mm, largely truncate at the base, rounded or truncate at the apex, deeply trilobed, cocci compressed, angular, keeled (sometimes weakly) on the dorsal side, yellowish at the end, glabrous, smooth or very finely granulate when dried. Seeds subglobose, 2.7 x 2.5 mm, base rounded or subtruncate, apex obtuse, facets convex, the dorsal side marked by longitudinally more or less sharp central keel, grayish or yellowish; caruncle absent.2