arenos (G.) = sand, + cola (L.) = dweller in, referring to the sandveld habitat of the species.
WCM Protologue Reference:
H.P.Linder, S. African J. Bot. 77: 417 (2011)
Vegetative parts: plants clumped or forming long lines of culms, 0.5-1 m tall, basal diameter 1-3 m, crown diameter 1-3 m, with rhizomes. Rhizome spreading, unbranched or sparsely branched, culms evenly spaced, 6-10 mm in diam., culms 6-10 mm apart. Fertile culms unbranched, smooth or finely rugulose, green or olivaceous, 0.5-1 m tall, diameter at base 1.5-2.5 mm, diameter at apex 0.8-1.5 mm. Sheaths closely convoluted, 15-25 mm long, brown with golden speckling, eventually turning grey, apical margins coriaceous, like the rest of the body, hyaline shoulders absent, apex, excluding the membranous lobes, acute. Sheath-mucro penicellate, straight and erect, 1.5-4 mm long, not very distinctive. Males: male inflorescence with 21-50 spikelets or 50-100 spikelets, paniculate, 30-70 mm long, 8-20 mm wide. Male inflorescence spathes caducous, taller than spikelets, chartaceous or cartilaginous, dropped very early in the maturation of the spikelets, but encloses the young spikelets. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, elliptical or ovate or orbicular, apex rounded, 3-4.5 mm, 2.5-4 mm, with 20-30 flowers, pedicels absent ie spikelets sessile or shorter than the spikelets, terete or angular. Male bracts shorter than flowers or as tall as flowers, 2.5-3.2 mm long, ovate, acute or acuminate, chartaceous, bract upper margin like body of bract or membranous, thinner texture than the body, bract awn minute or absent, as tall as male flowers, and only partially obscuring the flowers. Male flower 2.2-2.6 mm long. Male tepals sepals more rigid than petals, chartaceous, petals chartaceous, oblong, inner and outer tepals the same length. Male outer lateral tepals conduplicate, glabrous. Anthers 1.8-2 mm long, exserted from the flowers. Pistillode absent. Females: female inflorescence linear, 15-70 mm long, 10-15 mm wide, with 1 spikelet or 2-5 spikelets. Female spathes longer than the spikelets, not obscuring spikelet, persistent, chartaceous or cartilaginous. Female spathellae inconspicuous or absent. Female spikelet sessile, elliptical, apex acute, 15-20 mm long, with 1 flowers, with 5-8 sterile bracts. Female bracts taller than flowers, 10-12 mm long, ovate, acute, bony, apical margin like rest of bract, same as body of bract, awn minute or absent. Female flower with a fleshy pedicel. Female tepals membranous, glabrous and smooth, smaller than nut and not obscuring the nut surface, midrib flush with the tepal body, apices truncate, inner and outer whorls the same length. Female outer lateral tepals like other tepals, 1-2 mm long. Female odd outer tepal broad-based, with small, variable lobe, 1-2 mm long. Female inner tepals broad-based, with small, variable lobe, 1-2 mm long. Staminodes absent. Styles plumose, white, 2. Style bases free. Ovary with 1 locule, indehiscent. Fruit: indehiscent fruits with a hard woody ovary wall. Perianth presence on fruits persistent, membranous, shorter than nut. Nut apex smooth, without a distinct cap, wall smooth, 7.2-9 mm long, 3.7-5.8 mm diam., shape in side view elliptical or obovate, shape in top view planoconvex in cross section, brown or black, mode of seed release for nutted plants nut popped out of bracts. Elaiosome present, white, 1-2 mm long, less than half as long as nut.