albus (L.) = white, + aristatum (L.) = awns, referring to the strikingly pale awns or bract apices found in some specimens.
WCM Protologue Reference:
(Nees) Mast., J. Linn. Soc., Bot. 8: 255 (1865)
Vegetative parts: plants clumped, 0.3–0.5 m tall, basal diameter 0.1–1 m, crown diameter 0.1–1 m, compact, without spreading rhizomes or stolons or with rhizomes. Rhizome very short with culms aggregated at base, 8–15 mm in diam., culms 1–5 mm apart. Fertile culms unbranched, round (not compressed) or compressed (flattened culms occasionally twisted.), smooth, green or olivaceous or speckled golden, 0.3–0.7 m tall, diameter at base 0.5–1 mm, diameter at apex 0.2–0.5 mm. Sheaths absent or one per culm, persistent, with no abscission line, closely convoluted or loosely convoluted (less often loosely convoluted, but does occur), 15–60 mm long, speckled brown, with broad yellow margins, apical margins coriaceous, like the rest of the body or narrowly membranous, hyaline shoulders absent or small, rounded, hyaline shoulder 0.1–0.2 of sheath body length, apex, excluding the membranous lobes, acute. Sheath-mucro absent or penicellate, straight and erect, 2–4 mm long, occurring singly, or not at all, along entire length of each culm. Males: male inflorescence with 2–5 spikelets or 6–10 spikelets, racemose or paniculate, 10–80 mm long, 5–20 mm wide. Male inflorescence spathes persistent, shorter than spikelets or as tall as spikelets or taller than spikelets, chartaceous or cartilaginous, Spathes purple-brown and pale at the margins, or pale throughout. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, elliptical or obovate or orbicular, apex rounded or obtuse (awns form a truncated or rounded apex, distinct from the spikelet apex formed by the body of the bracts), 7–15 mm, 5–15 mm, with 30–40 flowers, pedicels absent ie spikelets sessile or as long as the spikelets, terete or angular. Male bracts taller than flowers, 5–10 mm long, oblong or ovate, acute or acuminate, cartilaginous, bract upper margin like body of bract or membranous, thinner texture than the body, 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, long, pale awns can be erect or distinctly recurved. Male flower 3.5–5 mm long. Male tepals sepals and petals the same rigidity, cartilaginous, linear or oblong, inner and outer tepals the same length. Male outer lateral tepals keeled or winged, glabrous. Anthers 1–3 mm long, exserted from the flowers. Pistillode absent. Females: female inflorescence linear or racemose, 10–30 mm long, 3–10 mm wide, with 1 spikelet or 2–5 spikelets. Female spathes shorter than the spikelets or as long as the spikelets or longer than the spikelets, not obscuring spikelet, persistent, chartaceous or cartilaginous. Female spikelet sessile, ovate, apex obtuse or acute, 7–14 mm long, with 1 flowers, with 15–30 sterile bracts. Female bracts taller than flowers, erect or reflexed, 4–8 mm long, oblong, acuminate, cartilaginous, apical margin membranous, paler than body of bract, awn less than half as long as the bract body or between half and as long as the bract body. Female flower 3.5–9 mm long, with a fleshy pedicel. Female tepals chartaceous or membranous, glabrous and smooth, smaller than nut and not obscuring the nut surface, midrib flush with the tepal body, apices acuminate (or truncated), inner whorl shorter than outer. Female outer lateral tepals like other tepals, 1–2 mm long. Female odd outer tepal ovate, 1–2 mm long. Female inner tepals ovate, 1–1.5 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 cap with several rows of ridges, wall tuberculate, (2.44–)3.21(–3.88) mm long, (2.28–)2.57(–3.32) mm diam., shape in side view elliptical, shape in top view round in cross section, brown. Elaiosome present, white, 1.5 mm long, less than half as long as nut.