nudus (L.) = naked, unclothed. Maybe referring the flowers not covered by bracts.
WCM Protologue Reference:
(Rottb.) Kunth, Enum. Pl. 3: 462 (1841)
Vegetative parts: plants clumped, 0.2-0.5 m tall, basal diameter 0.2-0.6 m, crown diameter 0.2-0.6 m, compact, without spreading rhizomes or stolons or with rhizomes (some plants have short spreading rhizomes). Rhizome very short with culms aggregated at base or spreading, unbranched or sparsely branched, culms evenly spaced, 1.5-2 mm in diam., culms 0-6 mm apart. Fertile culms unbranched, round (not compressed) or compressed, solid or with a small central cavity, smooth or finely rugulose, green or olivaceous, 0.2-0.5 m tall, diameter at base 0.5-1.7 mm, diameter at apex 0.2-1.2 mm. Branch axil indumentum absent. 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, 8-16 mm long, margins entire, glossy light brown to dark reddish-brown, apical margins narrowly membranous, hyaline shoulders absent, apex, excluding the membranous lobes, acuminate or acute. Sheath-mucro penicellate, straight and erect, 1-3 mm long. Males: male inflorescence with 21-50 spikelets or 50-100 spikelets, paniculate, 15-80 mm long, 6-9 mm wide. Male inflorescence spathes caducous, taller than spikelets (spathes are longer than individual spikelets but not very large), cartilaginous. Male spathellae inconspicuous or absent. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, undifferentiated, apex undifferentiated, 1.8-2.3 mm, 1.3-2 mm, with 1-3 flowers, pedicels shorter than the spikelets or as long as the spikelets, terete or angular or flattened. Male bracts shorter than flowers, 1-1.5 mm long, orbicular, rounded, margins entire, chartaceous, bract upper margin like body of bract, bract awn minute or absent. Male flower 1.6-2 mm long. Male tepals sepals and petals the same rigidity, chartaceous, oblong or elliptical, inner tepals longer than outer tepals. Male outer lateral tepals conduplicate, glabrous. Anthers 1-1.2 mm long, included in the flowers. Females: female inflorescence interrupted or linear, 10-110 mm long, 6-9 mm wide, with 11-20 spikelets or 21-50 spikelets or 51-100 spikelets. Female spathes longer than the spikelets (though relatively small), not obscuring spikelet, caducous, cartilaginous. Female spathellae inconspicuous or absent. Female spikelet pedicel sparsely branching, undifferentiated, apex undifferentiated, 2.3-2.8 mm long, with 3-5 flowers, with 0 sterile bracts. Female bracts shorter than flowers, erect, 1.3-1.9 mm long, ovate (broadly), obtuse or acute or acuminate, coriaceous or cartilaginous, apical margin like rest of bract, same as body of bract, margins entire, awn minute or absent. Female flower 1.6-2.4 mm long, without a fleshy pedicel, six tepals. Female tepals bony, scabrid all over or glabrous and smooth (tepals with ornamentation all over, certainly not smooth), midrib raised, margins entire, apices acuminate, inner whorl longer than outer. Female outer lateral tepals conduplicate, hidden by bracts, or bracts are shorter than flowers, 1.4-1.6 mm long. Female odd outer tepal oblong, 1.4-1.6 mm long. Female inner tepals elliptical, 1.6-2.4 mm long. Staminodes present. Styles feathery, 3. Style bases free. Ovary with 3 locules, dehiscent. Fruit: seed (0.55-)0.72(-0.86) mm long, (0.4-)0.51(-0.6) mm in diameter, shape in side view elliptical, shape in diameter round in cross section, brown.