Vegetative parts: plants tangled, 0.2–1.5 m tall, basal diameter 1–6 m, crown diameter 1–6 m, with stolons. Fertile culms branching, round (not compressed), solid or with a small central cavity, smooth or finely warty (at high magnification surface may look slightly patterned, uneven, with very flattened papillae), green, 0.2–0.6 m tall, diameter at base 0.9–4 mm, diameter at apex 0.4–1.1 mm. Branch axil indumentum present. 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, 6–38 mm long, margins entire, orange- to reddish-brown with very fine tan speckles, upper 1/3 in colour and texture similar to the lower 2/3, apical margins coriaceous, like the rest of the body or narrowly membranous, hyaline shoulders absent, apex, excluding the membranous lobes, acute. Sheath-mucro penicellate or hair-like, straight and erect, 1–5 mm long. Males: male inflorescence with 2–5 spikelets or 6–10 spikelets or 11–20 spikelets or 21–50 spikelets, racemose or paniculate or globose (rarely globose), 15–75 mm long, 3–12 mm wide. Male inflorescence spathes persistent, shorter than spikelets or as tall as spikelets, cartilaginous. Male spathellae inconspicuous or absent. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, oblong or elliptical, at least some curved, apex acute or undifferentiated, 4.5–10 mm, 0.9–1.6 mm, with 6–16 flowers, pedicels absent ie spikelets sessile or shorter than the spikelets or as long as the spikelets, flattened. Male bracts taller than flowers, 2.4–6.7 mm long, elliptical or ovate or obovate, rounded or obtuse, chartaceous or cartilaginous, bract upper margin membranous, thinner texture than the body, bract awn less than half as long as the bract body. Male flower 2–4.1 mm long. Male tepals sepals and petals the same rigidity or sepals more rigid than petals, cartilaginous, petals chartaceous, linear or elliptical or ovate, inner tepals shorter than outer tepals or inner and outer tepals the same length. Male outer lateral tepals conduplicate, keel sparsely villous. Anthers 1.1–2 mm long, exserted from the flowers. Females: female inflorescence interrupted or linear, 6–40 mm long, 2–12 mm wide, with 1 spikelet or 2–5 spikelets. Female spathes shorter than the spikelets or as long as the spikelets, persistent, coriaceous or cartilaginous. Female spathellae inconspicuous or absent. Female spikelet sessile or pedicel simple, orbicular or undifferentiated, apex undifferentiated, 6–20 mm long, with 6–15 flowers, with 0–1 sterile bracts. Female bracts taller than flowers, erect, 6.5–12 mm long, oblong or ovate or obovate, rounded or obtuse, coriaceous or cartilaginous, apical margin membranous, same as 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 4–5–8 mm long, without a fleshy pedicel, six tepals. Female tepals coriaceous or chartaceous or cartilaginous, keels of lateral sepals sparsely villous or keels of lateral sepals densely villous, midrib raised, apices acute, inner and outer whorls the same length or inner whorl shorter than outer. Female outer lateral tepals conduplicate, 4–5.8 mm long. Female odd outer tepal ovate, 4–5.8 mm long. Female inner tepals ovate, 3.6–5.6 mm long. Staminodes absent. Styles feathery, white, 2. Style bases fused to form a pillar. Ovary with 2 locules or 1 locule, dehiscent. Fruit: seed see I. Sieberi, see I. sieberi, colliculate or striate (little bumps arranged longitudinally in 'stripes).