setiger (L.) = having bristles, bristly. Referring to the spikelets, with acuminate awns which gives them a bristly appearance.
WCM Protologue Reference:
Kunth, Enum. Pl. 3: 385 (1841)
Vegetative parts: plants tufted or tangled, 1.1–1.3 m tall, basal diameter 0.5 m, crown diameter 1–2 m, compact, without spreading rhizomes or stolons. Fertile culms branching, round (not compressed), solid or with a small central cavity, roughly warty (pappilae are rather flattened), olivaceous, 1–1.3 m tall, diameter at base 2.8–3.5 mm, diameter at apex 1.1–1.6 mm. Branch axil indumentum absent. Clusters of sterile branches at the nodes of the fertile branches absent. Sheaths persistent, with no abscission line, closely convoluted, 15–35 mm long, margins entire, orange/reddish-brown with densely spaced tan speckles, apical margins broadly membranous, hyaline shoulders tall, acute, apex, excluding the membranous lobes, acuminate (tapering up into the awn). Sheath-mucro hair-like (very long and slender), straight and erect or recurved or twisted (due to its length the mucro may be recurved or twisted), 8–15 mm long, these are quite a distinguishing feature of the species. Males: male inflorescence with 6–10 spikelets or 11–20 spikelets or 21–50 spikelets, globose, 20–30 mm long, 6–12 mm wide. Male inflorescence spathes persistent, taller than spikelets, cartilaginous. Male spathellae inconspicuous or absent or conspicuous (?). Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, undifferentiated, at least some curved, apex undifferentiated, 5–12 mm (very long bract awns), 1.5–2 mm (this does not take the spreading awns into account), with 10–30 flowers, pedicels shorter than the spikelets, flattened. Male bracts taller than flowers, 4.5–7 mm long, elliptical or orbicular, rounded or acuminate (often the apex tapers into the awn), margins entire, coriaceous or chartaceous (actually a combination of these - neither thick nor membranous, but of medium thickness, and flexible), bract upper margin membranous, thinner texture than the body, bract awn longer than the bract body, the awns are recurved, giving the spikelets a very distinctive appearance. Male flower 2–2.8 mm long. Male tepals sepals more rigid than petals (the outer conduplicate tepals are generally more rigid due to the reinforcement of the midrib), chartaceous, petals chartaceous, elliptical or ovate (the outer conduplicate tepals are sometimes ovate, otherwise elliptical, while the odd outer and inner tepals are elliptical), inner tepals shorter than outer tepals or inner and outer tepals the same length (sometimes inner are slightly shorter than outer ones). Male outer lateral tepals conduplicate, keel sparsely villous. Anthers 1.2–1.6 mm long, exserted from the flowers. Females: female inflorescence interrupted, 20–45 mm long, 4–20 mm wide, with 1 spikelet or 2–5 spikelets. Female spathes shorter than the spikelets or as long as the spikelets, persistent, coriaceous. Female spikelet sessile, undifferentiated, apex undifferentiated, 15–30 mm long, with 5–30 flowers, with 1 sterile bracts. Female bracts taller than flowers, erect (the length and curvature of the female bract awns distinguishes I. ocreata quite clearly from I. setiger: the former has shorter and recurved awns), 11–15 mm long, oblong, obtuse or acuminate (tapering into the awn from a wide angle), coriaceous, apical margin membranous, same as body of bract, margins entire, awn longer than the bract body (the length and curvature of the female bract awns distinguishes I. ocreata quite clearly from I. setiger: the former has shorter and recurved awns). Female flower 3.5–7.5 mm long, without a fleshy pedicel, six tepals. Female tepals coriaceous, keels of lateral sepals sparsely villous, midrib raised, margins entire, apices acute, inner and outer whorls the same length. Female outer lateral tepals conduplicate, 3.2–7 mm long. Female odd outer tepal ovate, 3.2–7 mm long. Female inner tepals ovate, 3.2–6.8 mm long. Staminodes absent. Styles feathery, 2. Style bases fused to form a pillar. Ovary with 2 locules, dehiscent. Fruit: seed (2–)2.11(–2.16) mm long, (1.08–)1.15(–1.24) mm in diameter, shape in side view oblong, shape in diameter triangular in cross section, translucent or yellow or tan (seedcoat is translucent so that the yellowish/tan seed with brown patches shines through), smooth.