Vegetative parts: plants mat-Forming or single isolated shoots or several much-branched culms from base (with stems spreading underground like in R. vallis-simii, thus resulting in a lawn-like growth), 0.2–0.6 m tall, with stolons. Fertile culms much branched, smooth or finely warty, olivaceous, 0.2–0.6 m tall, diameter at base 0.9–3 mm, diameter at apex 0.2–1 mm. Sheaths closely convoluted or loosely convoluted, 5–25 mm long, brown, apical margins narrowly membranous or broadly membranous, hyaline shoulders tall, acute, hyaline shoulder 0.3–0.6 of sheath body length, apex, excluding the membranous lobes, acute or obtuse. Sheath-mucro penicellate, straight and erect, 2–5 mm long, usually looselyb wrapped around the culm. Males: male inflorescence with 1 spikelet or 2–5 spikelets or 6–10 spikelets, racemose (but the whole upper culm area much branched), 5–50 mm long, 5–10 mm wide. Male inflorescence spathes persistent, like the floral bracts, coriaceous. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, oblong or ovate, apex rounded or obtuse, 5–11 mm, 2.5–6 mm, with 2–12 flowers, pedicels absent ie spikelets sessile or shorter than the spikelets, terete or angular. Male bracts shorter than flowers, 2–3.5 mm long, oblong or ovate, obtuse or acute, margins shallowly toothed, cartilaginous, bract upper margin with honeycombed cells, which eventually decay. Male bract ciliate. Male bract awn minute or absent, ciliate margins lost almost immediately. Male flower 2.4–3 mm long. Male tepals sepals more rigid than petals, cartilaginous, petals membranous, oblong, inner and outer tepals the same length. Male outer lateral tepals conduplicate, keel sparsely villous or keel densely villous. Anthers 1.2–1.6 mm long, exserted from the flowers. Pistillode present. Females: female inflorescence racemose (But with culms below the inflorescences much branched), 5–40 mm long, 3–15 mm wide, with 1 spikelet or 2–5 spikelets. Female spathes shorter than the spikelets, persistent, coriaceous. Female spikelet sessile, oblong or ovate, apex rounded, 4.5–10 mm long, with 2–12 flowers, with 0–2 sterile bracts. Female bracts shorter than flowers or as tall as flowers, 2–4 mm long, ovate, acute. Female bract ciliate. Female bracts chartaceous or cartilaginous, apical margin like rest of bract, same as body of bract, margins entire or shallowly lacerated or toothed, awn minute or absent. Female flower 2.8–4 mm long, without a fleshy pedicel. Female tepals cartilaginous, keels of lateral sepals sparsely villous, midrib flush with the tepal body, apices rounded, inner and outer whorls the same length. Female outer lateral tepals conduplicate, exserted past bracts, 2.8–4 mm long. Female odd outer tepal oblong, 2.6–3.8 mm long. Female inner tepals oblong or ovate, 2.5–3.3 mm long. Staminodes present. Styles feathery, 3. Style bases free. Ovary with 3 locules, dehiscent. Fruit: seed (1.08–)1.25(–1.4) mm long, (0.6–)0.81(–1) mm in diameter, shape in side view elliptical, shape in diameter triangular in cross section, brown.