Commiphora namibensis Swanepoel

Swanepoel, W., 2014, Commiphora namibensis (Burseraceae), a new species from Angola, Phytotaxa 178 (3), pp. 211-216: 211-214

publication ID

http://doi.org/ 10.11646/phytotaxa.178.3.7

persistent identifier

http://treatment.plazi.org/id/03F487DD-751A-FFD2-9AEA-F93BDFDAFF03

treatment provided by

Felipe

scientific name

Commiphora namibensis Swanepoel
status

sp. nov.

Commiphora namibensis Swanepoel   sp. nov. ( Figs.1 View FIGURE 1 & 2 View FIGURE 2 )

Differs from C. virgata Engler   in branches and branchlets mostly spinescent; leaves trifoliolate, rarely with few simple ones also present, leaflets shiny adaxially, slightly discolorous, obovate, obcordate, subrhombic, suborbicular or broadly elliptic; disc grooved in male flowers; putamen laterally slightly compressed; pseudo-aril yellow.

Type: — ANGOLA. Namibe Province: 13 km west of Caraculo along main road to   Namibe, 1512 BA, 526 m, 14 April 2010   , Swanepoel   329 (holotype PRU!; isotype LUBA!)     .

Dioecious shrub-like tree 0.4–3 m tall, 1–7 m diam. Trunk simple and short, up to 1 m long, 0.35 m diam., branching into relatively thick stems. Bark yellowish white to khaki, peeling around stems and older branches in papery strips exposing green to coppery brown under bark with light brown horizontal lenticels; on branches and branchlets brown, grey-brown, reddish brown or grey. Branches and branchlets glabrous with few small, prominent lenticels, mostly spinescent, dwarf lateral branchlets scarred. Exudate clear (achromatic), scant, drying to form a hard, pale yellow, translucent resin. Leaves mostly trifoliolate, rarely few simple leaves also present, clustered on branches, spines and on dwarf lateral branchlets but spirally on actively elongating shoots, petiolate, lamina green, shiny adaxially, slightly discolorous, glabrous or with very few short glandular hairs, leaflets sessile or subsessile, often sub-patent and suberect, 0.9–1.6 times as long as broad; lamina of simple leaves ovate or broadly elliptic, apex acute, emarginate or rounded, base cuneate 14–26 × 12–20 mm, lamina of terminal leaflets obovate, obcordate, subrhombic or suborbicular, apex acute, rounded, truncate or emarginate, often shortly acuminate, base cuneate or rounded, 6–34 × 5–28 mm, lamina of lateral leaflets broadly elliptic, obovate, obcordate or suborbicular, often asymmetric, apex rounded, acute, truncate or emarginate, often shortly acuminate, base cuneate or rounded 4–24 × 3–18 mm, terminal and lateral leaflets with margins entire or with 1 or 2 serrations each side towards apex, lateral leaflets smaller than terminal leaflet; midrib and lateral veins conspicuous on both sides, yellow-green; petiole glabrous, 3–27 mm long, pentagonal, trigonal or suborbicular in transverse section with 9–14 vascular bundles, sectional dimensions 0.7–1.5 × 0.6–1.4 mm. Inflorescence s: axillary, clustered, flowers solitary or in reduced simple cymes, peduncle 0.5–0.7 mm long, glabrous. Flowers precocious, unisexual, hypogynous, subsessile, all parts glabrous. Bracts crescentic or semi-circular, 0.5–1.2 × 0.3–0.6 mm, margins with short glandular hairs. Calyx green, lobes deltoid, acute. Male flowers 3.5–4.5 mm long, calyx 1.5–1.8 mm long, calyx lobes ± 0.4 mm long, petals 3.5–3.9 × 1.0– 1.2 mm (when flattened), abrubtly spreading near apex, minute tip inflexed; disc cylindrical, not adnate to perianth, grooved on inside, fleshy with 4 distinct lobes, lobes not bifid; stamens 8, filaments filiform, 4 long stamens with filaments 2.2–2.6 mm long, inserted high up on outer margin of disc lobes, 4 short stamens with filaments 1.3–1.5 mm long, inserted between lobes on outer margin of disc, anthers on long stamens 0.8–0.9 mm long, on short stamens 0.6–0.7 mm long; gynoecium rudimentary, ± 0.2 long. Female flowers 2.7–3.6 mm long, 1.2–1.5 mm diam., calyx 1.3–1.7 mm long, calyx lobes 0.4–0.7 mm long, petals 2.2–3.0 × 0.7–1.1 mm, abrubtly spreading near apex, minute tip inflexed; disc with 4 distinct, short lobes, lobes not bifid; staminodes 8, alternately long and short; ovary ovoid or ellipsoid, style relatively long, stigma obscurely 4- lobed; pistil equal in height to petals (top of flower), 2.0– 2.4 mm long, 1.1–1.4 mm diam. Fruit a drupe, subglobose, suture convex, 6.0–8.2 × 5.0– 6.4 mm; pericarp 2-valved; exocarp glabrous, cherry-red when ripe; mesocarp not very fleshy; putamen black, asymmetrical, laterally slightly compressed, rugose, ellipsoid or obovoid with one fertile and one sterile locule, 4.2–5.5 × 3.0–4.1 × 3.5–4.4 mm; fertile locule convex in apical and lateral view; sterile locule triangular in apical view, prominently keeled, especially towards apex; suture convex towards fertile locule; pseudoaril yellow, covering putamen base, with 4 long arms reaching the apex; apical pits large.

Phenology: — Commiphora namibensis   flowers in November and December.

Distribution and habitat: — Commiphora namibensis   is presently known from various localities in the coastal zone of southwestern Angola from Namibe to ± 40 km inland and northwards to Santa Maria ( Fig. 3 View FIGURE 3 ). This arid area falls within the Kaokoveld Centre of Plant Endemism ( Van Wyk and Smith, 2001) and is part of the Namib Desert. C. namibensis   is uncommon and occurs with several other species of Commiphora   on mountain slopes and level areas, in arid bushveld and desert shrubland at elevations of 20– 600 m.

Conservation status: — Commiphora namibensis   is not under any threat as the plants are located in remote, sparsely populated areas.

Etymology: —The specific epithet refers to the Namib Desert which, in its broadest definition, stretches along the Atlantic Ocean from San Nicolau in Angola through Namibia to the Olifants River in South Africa ( Seely 2004). The Namibe Province, one of the two politically demarcated provinces of Angola in which the new species occurs, as well as the town with the same name, is also named after the Namib Desert.

BA

Museo Argentino de Ciencias Naturales Bernardino Rivadavia

PRU

University of Pretoria

LUBA

Instituto Superior de Ciencias da Educação