Description from Flora of China
Eleocharis pauciflora (Lightfoot) Link var. rhizomatosa Handel-Mazzetti.
Perennials. Rhizomes thick, decumbent to obliquely ascending. Culms laxly to densely tufted, 16-40 cm tall, ca. 1 mm thick, terete, longitudinally sulcate. Leaf sheaths 3, basalmost glumelike; cauline sheaths 2, tubular, 2-8 cm, basally purplish red to purple, apically green, mouth slightly obliquely truncate. Spikelet narrowly oblong to oblong, 6-8 × 2-3 mm, few flowered. Basal 2 glumes opposite, 1/2 or more as long as spikelet; basalmost glume usually proliferous but without a flower and next one both proliferous and with a flower; fertile glumes blood-red, spirally imbricate, ovate-lanceolate, 3-4 × ca. 1.3 mm, midvein conspicuous to obscure, margin pale blood-red and broadly hyaline, apex acute. Perianth bristles 6, pale rust-colored, as long as nutlet, densely retrorsely shortly spinulose. Stigmas 3. Nutlet yellowish green, obovoid, 1.2-1.5 × 0.6-0.8 mm, obtusely 3-sided, sides slightly convex, apex constricted, ± narrow, and as wide as base of style; persistent style base pale, narrowly 3-angled to conic, ca. 1/2 as long as nutlet, apex attenuate to a short caudal tip. Fl. and fr. Apr-Aug.
● River margins in valleys; 1800-3300 m. Yunnan.