Rhynchospora caduca Elliott

Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. Culms erect or ascending, leafy, trigonous. Leaves exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. Inflorescences terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. Spikelets rich brown, ovoid, (3–)4–5 mm, apex acuminate; fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or short excurrent. Flowers: perianth bristles mostly 6, exceeding tubercle tip. Fruits mostly 3–4 per spikelet, 2–2.2 mm; body brown on short pedicellar (to 0.3 mm) stalk, broadly obovoid, lenticular, 1.3–1.5 × 1–1.5 mm, surfaces transversely rugulose, vertically finely striate and rectangular alveolate; tubercle compressed, triangular acuminate, 0.5–0.8 mm, edges setulose.