virgate (L.) = branching, after the branching habit of the plants.
WCM Protologue Reference:
(Rottb.) Steud., Syn. Pl. Glumac. 2: 263 (1855)
Vegetative parts: plants clumped or mat-Forming, 1-1.5 m tall, basal diameter 3-6 m, crown diameter 3-6 m, with rhizomes. Rhizome spreading, unbranched or sparsely branched, culms evenly spaced, 7.5-10 mm in diam., culms 8-35 mm apart. Fertile culms sparingly branched or branching, round (not compressed) or compressed, distinctly hollow (central cavity distinct, but smaller than that of C. grandis), smooth or finely rugulose, green or olivaceous, 1-1.5 m tall, diameter at base 5-8.5 mm, diameter at apex 0.5-2.1 mm. Clusters of sterile branches at the nodes of the fertile branches present. Sterile branches present while flowering. Sheaths closely convoluted, 10-65 mm long, brown, upper 1/3 in colour and texture similar to the lower 2/3 or abruptly different from the base, and soon decaying, apical margins coriaceous, like the rest of the body or narrowly membranous, hyaline shoulders absent, apex, excluding the membranous lobes, acuminate or acute or obtuse. Sheath-mucro penicellate or awl- or needleshaped, straight and erect, 2-10 mm long, Nervose-striate, with the upper third sometimes lighter than the lower part. Males: male inflorescence with 21-50 spikelets or 50-100 spikelets or 101-500 spikelets, paniculate, 60-400 mm long, 15-70 mm wide. Male inflorescence spathes caducous, taller than spikelets, coriaceous or cartilaginous. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, oblong or elliptical or ovate, apex acute, 4-7.2 mm, 3-4 mm, with 10-40 flowers, pedicels shorter than the spikelets or as long as the spikelets, terete or angular or flattened. Male bracts as tall as flowers, 2-3 mm long, ovate, acute or acuminate, chartaceous or cartilaginous, bract upper margin membranous, thinner texture than the body, bract awn minute or absent or less than half as long as the bract body. Male flower 2-3 mm long. Male tepals sepals more rigid than petals, membranous, petals membranous, oblong or ovate, inner and outer tepals the same length. Male outer lateral tepals conduplicate, glabrous. Anthers 1.5-2 mm long, exserted from the flowers. Females: female inflorescence with 1 spikelet. Female spathes shorter than the spikelets, persistent, coriaceous or chartaceous or cartilaginous. Female spathellae inconspicuous or absent. Female spikelet sessile, elliptical or obovate, apex acute, 15-45 mm long, with 2-3 flowers, with 7-8 sterile bracts. Female bracts taller than flowers, erect, 16.5-24 mm long, oblong or ovate, acuminate, bony or coriaceous, apical margin membranous, same as body of bract or darker than body of bract, awn less than half as long as the bract body. Female flower with a fleshy pedicel, six tepals. Female tepals membranous, glabrous and smooth, at least as tall as nut, wrapped around it and obscuring the surface, midrib flush with the tepal body, margins entire, apices rounded or obtuse, inner and outer whorls the same length. Female outer lateral tepals like other tepals, hidden by bracts, or bracts are shorter than flowers, 6.8-14.3 mm long. Female odd outer tepal oblong, 6.8-14.3 mm long. Female inner tepals oblong, 6.8-14.3 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, as tall as nuts. Nut apex smooth, without a distinct cap, wall smooth, 9-12 mm long, 5-7 mm diam., shape in side view elliptical, shape in top view planoconvex in cross section, black. Elaiosome present, white, 0.7-1.1 mm long, less than half as long as nut.