Euphorbia otjipembana Leach 1976
Creators: name: Swanepoel, Wessel
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malpighiales
Euphorbiaceae
Euphorbia
Euphorbia otjipembana

description: Euphorbia otjipembana Leach (1976: 29)   
 Type: ― NAMIBIA. Kunene Region: Stony eastern slopes of Baynes Mountains, north of Otjipemba, 1712 BB, 21 July 1973, Leach & Cannell 15044 (holotype PRE!, isotypes BM, K, LISC, M, MO, SRG, WIND!).   
Succulent, spiny shrub with fresh green or grey-green epidermis, up to 1 m tall, diam. up to 2 m. Trunk single, nude for 30–200 mm or multi-stemmed from ground level. Bark on trunk grey, on branches and central stem fresh green or grey-green, grey towards base. Branches numerous, ascending, occasionally slightly spirally twisted, 0.15–0.8 m long, 18–35 mm diam., constricted at base, slightly or not constricted into segments, 20– 60 mm long, 4–7-angled, 3–5-angled on branchlets, angles compressed, sometimes wing-like, margins even, slightly sinuate, serrate or crenate-serrate, with horny spine shields and spines; secondary branches on apical two thirds of branches. Spine shields decurrent, ± rectangular between lower and upper spine pairs, abruptly narrowing below lower pair, narrowly cuneate or ± parallel-sided towards base, or cuneate from apex towards base, separate initially, eventually forming a subcontinuous or continuous horny margin, 2.0– 5.2 mm wide, 5– 15 mm long (when separate); spines paired, lower pair diverging, ± horizontally spreading, 4–15 mm long, ± regularly arranged, 5–14 mm apart along angles; upper pair shorter, 0.8–7 mm long, from very widely divergent to parallel and perpendicular to spine-shield, straight or down-curved, often projecting ± 45º upwards, one or more short (up to 5 mm long) or rudimentary spines sometimes present towards base of spine shield. Leaves deciduous, sessile, green, cherry-green or yellow-pink, semi-circular, ovate to broadly trullate or pentagonal, apex often apiculate, margin entire or irregularly dentate, thick, stiff, curved towards abaxial side, 0.8–1.6 × 0.6–1.6 mm; scar elliptic, triangular or oblong-elliptic. Inflorescences cymose, occasionally compound, yellow, cherry-red, greenish red or reddish yellow, glabrous, with single, shortly pedunculate cymes, each comprising three horizontally arranged cyathia; peduncle bibracteate, up to 3.0 mm long; bracts semi-circular, obovate or rectangular, margin irregularly denticulate, crenulate or fimbriate-denticulate, not thickened or thickened towards base, caducous and leaving prominent scar, 1.0–2.5 × 1.4–2.5 mm; central initial cyathium male and marcescent, bisexual laterals borne on bibracteate cyme branches up to 3 mm long; bracts obovate, ± rectangular or triangular, not thickened or thickened towards base, caducous and leaving prominent scar, 1.4–2.0 × 1.1–1.8 mm, margin irregularly denticulate. Involucre obconic, in male cyathium laterally compressed by laterals, 2.3–2.7 mm long, 2.4–3.2 mm diam. including glands, in bisexual cyathia 1.4–3.6 mm long, 2.8–4.0 mm diam. including glands; glands 5(–6), slightly fleshy or fleshy, erect, sub-erect or spreading, separate or contiguous, suborbicular, transversely ± oblong, oblong-elliptic or elliptic, 0.7–2.1 × 0.5–0.8 mm, smaller in male cyathium than in bisexual, concave adaxially, convex abaxially, yellow, yellowish pink or yellowish red, upper surface rugulose, margin broad in male cyathium, narrower in bisexual cyathia, ± entire, irregularly crenate or crenulate; lobes 5(–6), glabrous, sub-quadrate, suborbicular or ± obovate, prominent to obscurely vertically ridged abaxially, margin at apex irregularly fimbriate, often 2–4- lobed, 1.0–1.5 × 1.0– 1.5 mm. Male flowers arranged in 5(–6) fascicles of 2(–3) flowers each opposite lobes, well exerted from involucre, subtended by filiform-laciniate bracteoles ± 1.3 mm long; each fascicle subtended and loosely enwrapped by a broad fimbriate-laciniate often 2–4-lobed bract, 2.0– 2.8 mm long, 2.2– 3.0 mm wide at apex; pedicels filiform, pale green, when fully developed ± 3.1 mm long in male cyathium, ± 2.2 mm long in bisexual cyathia; filaments terete, maroon or green, 1–1.7 mm long; anther thecae orbicular, flattened, orange-red or pale brown, 0.8 mm diam., pollen bright yellow. Female flowers erect, glabrous; ovary elliptic or oblong-elliptic, trigonous, occasionally 4-angled, green, 0.9–1.0 mm long, 1.0– 1.3 mm diam., included in involucre, subsessile on short, triangular, quadrate or pentagonal pedicel, ± 0.5 × 0.9 mm diam. Ovule ± elliptic, ± 0.6 × 3.0 mm diam., suspended under triangular or oblong ± 0.3 mm long obturator, margin irregularly denticulate-fimbriate; female flower rudimentary in male cyathium; styles 3(–4), ascending spreading, 1.7–2.6 mm long, united into stout column for 0.3–0.7 mm, apex shortly bifid, stigmas rugulose granulose. Capsule 3(–4)-locular, deeply lobed, elliptic or ovate, apex emarginate, truncate or obtuse, greenish red or greenish yellow, with pale dots, 3.0–3.8 × 3.2–4.3 mm, held erect, exerted from involucre but base within, on a stout pedicel, green, ± 2.5 mm long, ± 2.3 mm diam.; perianth reduced to a pentagonal obconic rim below the capsule, whitish, ± 1.3 mm high, 2.3–2.8 mm diam. Seed narrowly ellipsoid, ovoid, obovoid, oblongoid or subglobose, verrucose-rugulose, pale brown, suture dark brown, 1.7–2.5 ×1.0–1.4 × 1.2–1.5 mm.
description: Published as part of Swanepoel, Wessel, 2013, Euphorbia otjipembana subsp. okakoraensis (Euphorbiaceae), a new subspecies from the Kaokoveld, Namibia, with an amplified description of Euphorbia otjipembana, pp. 51-57 in Phytotaxa 117 (2) on page 52, DOI: 10.11646/phytotaxa.117.2.3, http://zenodo.org/record/5079216