tenuissimus (L.) = very slender, most slender. Referring to the very thin culms.
WCM Protologue Reference:
Kunth, Enum. Pl. 3: 394 (1841)
Vegetative parts: plants tangled, 0.1–0.25 m tall, basal diameter 0.1–0.3 m, crown diameter 0.1–0.3 m, compact, without spreading rhizomes or stolons or with stolons. Fertile culms branching or much branched, round (not compressed) or compressed (can be both), solid or with a small central cavity, rugose or roughly warty, green, 0.1–0.25 m tall, diameter at base 0.2–0.8 mm, diameter at apex 0.1–0.4 mm, terminal parts flexuose or straight. Branch axil indumentum absent. Clusters of sterile branches at the nodes of the fertile branches absent. Sheaths more than 1 per culm, persistent, with no abscission line, closely convoluted or loosely convoluted, 3–20 mm long, greenish/tan/light-brown/brown with darker speckles, upper 1/3 in colour and texture similar to the lower 2/3, apical margins coriaceous, like the rest of the body, hyaline shoulders absent, apex, excluding the membranous lobes, truncate. Sheath-mucro penicellate, straight and erect or recurved (depending on length), 1–12 mm long. Males: male inflorescence with 2–5 spikelets or 6–10 spikelets, racemose, 0.5–0.85–30 mm long, 0.5–0.8 mm wide. Male inflorescence spathes persistent, shorter than spikelets or as tall as spikelets or taller than spikelets, coriaceous or cartilaginous (though quite thin). Male spathellae inconspicuous or absent. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, elliptical, apex acute or undifferentiated, 2–2.5 mm, 0.35–0.5 mm, with 1 flowers, pedicels absent ie spikelets sessile. Male bracts taller than flowers, 2–2.5 mm long, oblong or ovate, acute, coriaceous or cartilaginous, bract upper margin membranous, thinner texture than the body, bract awn less than half as long as the bract body. Male flower 1.8–2.3 mm long. Male tepals sepals and petals the same rigidity, chartaceous, inner and outer tepals the same length. Male outer lateral tepals as other tepals, glabrous. Anthers 1–1.5 mm long, exserted from the flowers. Females: female inflorescence interrupted, 5–40 mm long, 1.5–4 mm wide, with 1 spikelet or 2–5 spikelets. Female spathes as long as the spikelets, persistent, coriaceous (but quite thin). Female spathellae inconspicuous or absent. Female spikelet sessile, orbicular or undifferentiated, apex undifferentiated, 2–5 mm long, with 1 flowers, with 1 sterile bracts. Female bracts as tall as flowers, erect, 3–4.8 mm long, oblong or elliptical, acute or acuminate, coriaceous or cartilaginous, apical margin membranous, same as body of bract, awn less than half as long as the bract body. Female flower 2–3.8 mm long, regular, without a fleshy pedicel, six tepals. Female tepals chartaceous, glabrous and smooth, midrib flush with the tepal body, apices rounded or acute, inner and outer whorls the same length or inner whorl shorter than outer. Female outer lateral tepals like other tepals, 2–3.8 mm long. Female odd outer tepal ovate, 2–3.8 mm long. Female inner tepals elliptical or ovate, 1.8–3.6 mm long. Staminodes absent. Styles feathery, white, 2. Style bases fused to form a pillar. Ovary with 1 locule, dehiscent. Fruit: seed (0.88–)1.1(–1.36) mm long, (0.68–)0.73(–0.8) mm in diameter, shape in side view elliptical, shape in diameter round in cross section, white, pitted (large round pits).