Description

Key Characters:

Growth Form: Perennials with short rhizomes.

Stems: culms biconvex, (30–)50–130 cm tall, 4–8 mm wide, smooth.

Roots:

Leaves: Leaves simple. Leaves equitant, primarily basal or nearly so, and with a single leaf about midway up the culm. Leaves as long as to slightly longer than the culm, 6–23 mm wide. Apex subacute. Surfaces smooth, pale green. Margins entire. Sheathing; sheaths brown. Stipules absent.

Flowers: Flowers in inflorescence a large decompound panicle 30–50 cm long, 8–16 cm wide, bearing 4–5 partial panicles, the panicle branches 2–13 together, exserted from the bract sheath, the longer ones up to 12 cm long, bracts shorter than the panicle, the sheath brown; spikelets congested in clusters of 2–4, each one turbinate in fruit, 7–8 mm long; glumes 5–8, dark brown, subcoriaceous, oblong–ovate, subobtuse, boatshaped with a conspicuous keel, indistinctly many–nerved, the lower 2 glumes small and empty, the middle 3–6 glumes flower–bearing, 3–4 mm long, the distal 1–2 glumes much–reduced. spikelets with with up to 3 flowers. Flowers bisexual (perfect) or staminate. Calyx (sepals) absent. Corolla (petals) absent. Stamens 3. Ovary superior; styles 3-cleft, the long style base pyramidal, pubescent.

Fruit: Achenes yellowish brown; narrowly ellipsoid; trigonous and slightly winged; 2.8–3.2 mm long (incl. stipe); the base attenuate to a 3–winged stipe ca. 1.5 mm long. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy: 2n = ca. 60*

Habitat: Occurring in wet forest and margins of bogs.

Elevation Range: 420–2,070 m.