argenteum (L.) = silver. In reference to the appearance of the male inflorescence with its silvery bracts.
WCM Protologue Reference:
Nees ex Kunth, Enum. Pl. 3: 483 (1841)
Vegetative parts: plants tufted, 2-3 m tall, basal diameter 0.3-1 m, crown diameter 1-1.5 m, with rhizomes. Rhizome spreading, unbranched or sparsely branched, culms evenly spaced, 8-10 mm in diam., culms 1-3 mm apart. Fertile culms unbranched, round (not compressed) or compressed after pressing, solid or with a small central cavity, smooth, green, 2-3 m tall, diameter at base 6-8 mm, diameter at apex 3-4 mm. Sheaths closely convoluted, 30-60 mm long, margins ciliate, green in lower 2/3, brown in upper 1/3, upper 1/3 in colour and texture abruptly different from the base, and soon decaying, apical margins narrowly membranous, hyaline shoulders absent, apex, excluding the membranous lobes, rounded or truncate. Sheath-mucro absent or penicellate, straight and erect, 3-4 mm long, cilia on lower sheaths to 3 mm long. Males: male inflorescence with 6-10 spikelets or 11-20 spikelets or 21-50 spikelets or 50-100 spikelets, paniculate, 100-130 mm long, 20-50 mm wide. Male inflorescence spathes caducous, taller than spikelets, cartilaginous, shiny brown, finely striate. Male flowers in spikelets or not aggregated into spikelets. Male spikelets erect on stiff pedicels or sessile, undifferentiated, apex undifferentiated, 7-14 mm, 4-10 mm, with 10-30 flowers, pedicels absent ie spikelets sessile or shorter than the spikelets, terete or angular. Male bracts taller than flowers, 5-10 mm long, linear, acute, membranous, bract upper margin like body of bract, bract awn minute or absent, straw-coloured. Male flower 5-8 mm long. Male tepals sepals and petals the same rigidity, membranous, linear, inner tepals shorter than outer tepals. Male outer lateral tepals as other tepals, glabrous. Anthers 1.5-3.5 mm long, included in the flowers. Pistillode present. Females: female inflorescence linear, 60-150 mm long, 10-40 mm wide, with 2-5 spikelets. Female spathes longer than the spikelets, obscuring spikelet, persistent, cartilaginous. Female spathellae inconspicuous or absent. Female spikelet sessile, obovate, apex truncate or rounded, 30-45 mm long, with 1 flowers, with 8-15 sterile bracts. Female bracts taller than flowers, erect, 30-45 mm long, ovate, acuminate, chartaceous, apical margin membranous, same as body of bract, margins entire, awn minute or absent. Female flower 2-2.5 mm long, without a fleshy pedicel, six tepals. Female tepals membranous, glabrous and smooth, smaller than nut and not obscuring the nut surface, midrib flush with the tepal body, margins entire, apices rounded or obtuse, inner and outer whorls the same length or inner whorl shorter than outer. Female outer lateral tepals like other tepals, hidden by bracts, or bracts are shorter than flowers, 2-3 mm long. Female odd outer tepal square or ovate, 2-3 mm long. Female inner tepals square or ovate, 2-2.5 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 apex smooth, without a distinct cap, wall tuberculate, 10-12 mm long, 8-9.5 mm diam., shape in side view elliptical, shape in top view round in cross section, brown. Elaiosome absent.