coleurus (L.) = a leather sack, liquid measure. Not at all clear what this means.
WCM Protologue Reference:
Nees ex Mast., Monogr. Phan. 1: 358 (1878)
Vegetative parts: plants 0.3–0.9 m tall, with rhizomes. Rhizome spreading, unbranched or sparsely branched, culms evenly spaced, 2.5–5 mm in diam., culms 6–15 mm apart. Fertile culms unbranched, compressed, solid or with a small central cavity, smooth, olivaceous, 0.3–0.85 m tall, diameter at base 1–2 mm, diameter at apex 0.4–1 mm. Clusters of sterile branches at the nodes of the fertile branches absent. Sheaths more than 1 per culm, dropping off, with an abscission line present, loosely convoluted, 15–35 mm long, margins entire, tan with reddish-brown speckles and tan margins, upper 1/3 in colour and texture similar to the lower 2/3, apical margins narrowly membranous, hyaline shoulders absent, apex, excluding the membranous lobes, acute. Sheath-mucro penicellate, straight and erect, 1.3–20 mm long, The sheaths are held conspicuously at a 45o angle before dropping, and the mucro varies greatly in length and thickness. Males: male inflorescence with 21–50 spikelets or 50–100 spikelets, paniculate, 25–85 mm long, 15–20 mm wide. Male inflorescence spathes caducous, taller than spikelets, cartilaginous. Male spathellae conspicuous, 6–14 mm long (there are two differently shaped kinds of spathellae - a slender elongated and a wider type). Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, undifferentiated, apex undifferentiated, 4–5.5 mm, 2–3.5 mm, with 1–4 flowers, pedicels as long as the spikelets, terete or angular. Male bracts as tall as flowers or taller than flowers, 2.5–3.5 mm long, ovate or orbicular, acuminate, chartaceous, bract upper margin like body of bract, bract awn less than half as long as the bract body or between half and as long as the bract body or longer than the bract body. Male flower 1.8–2.2 mm long. Male tepals sepals and petals the same rigidity, cartilaginous, ovate, inner tepals longer than outer tepals. Male outer lateral tepals conduplicate, glabrous. Anthers 0.9–1.1 mm long, included in the flowers. Females: female inflorescence linear, 15–55 mm long, 10–20 mm wide, with 11–20 spikelets or 21–50 spikelets. Female spathes longer than the spikelets, not obscuring spikelet or obscuring spikelet, persistent, cartilaginous. Female spathellae conspicuous, 7–10 mm long (includes both narrowly ovate and broadly ovate spathellae). Female spikelet pedicel simple, orbicular, apex undifferentiated, 6–7.5 mm long, with 4–6 flowers, with 0 sterile bracts. Female bracts shorter than flowers, erect, 2.5–3.5 mm long, orbicular, rounded or obtuse, chartaceous or membranous, apical margin membranous, paler than body of bract, awn less than half as long as the bract body. Female flower 1.7–2.1 mm long, without a fleshy pedicel, six tepals. Female tepals chartaceous or membranous (upper tepal margins membranous), glabrous and smooth, at least as tall as nut, wrapped around it and obscuring the surface, midrib raised, margins entire, apices rounded or obtuse or acute, inner and outer whorls the same length. Female outer lateral tepals like other tepals (but with raised midrib looking conduplicate), 1.5–2.1 mm long. Female odd outer tepal oblong or ovate, 1.5–2.1 mm long. Female inner tepals oblong or elliptical, 1.5–2.1 mm long. Staminodes absent. Styles white, 3. Style bases free. Ovary with 1 locule, indehiscent. Fruit: indehiscent fruits with a softer ovary wall. Nut apex smooth, without a distinct cap, wall smooth or wall tuberculate, (1.16–)1.36(–1.6) mm long, (0.76–)0.94(–1) mm diam., shape in side view elliptical, shape in top view triangular in cross section, brown. Elaiosome absent.