Description

Key Characters:

Growth Form: Rhizomatous perennials forming large, dense clumps.

Stems: Culms trigonous, (15–)40–100 cm tall, bearing spikes ⅓–1⁄2 from base upwards.

Roots:

Leaves: Leaves simple. 3-ranked, up to 8 per culm. Blades linear, flat 1.5–2 mm wide. Apex gradually tapering and long-acuminate. Upper surfaces deep green; lower surfaces scabrous on veins; blades coriaceous. Margins entire. Sheathing; sheaths laxly surrounding culm bases, reddish brown to dark brown, disintegrating into parallel fibers. Stipules absent.

Flowers: Flowers in inflorescences (2–)4–9(–14)–nodose, with internodes 2–5 cm long, the spikes solitary at nodes, nodes occasionally with 2 spikes or with 3 secondary spikes, each spike pedunculate, cylindrical, 0.8–1.5 cm long, up to 5 mm wide, the terminal spike staminate, lateral ones androgynous or pistillate; bracts leaf-like, the lower 1–3 slightly longer than the inflorescence, long–sheathing at base; pistillate glumes brown, membranous, ovate, 2.5–5 mm long, margins hyaline, the midnerve prolonged into a scabrous awn 3–5 mm long; perigynium chartaceous to subcoriaceous, green to yellowish green, or reddish brown to dark red, ellipsoid to obovoid or broadly obovoid, (3–)5–8 mm long, 1–4 mm wide, many–veined, obtusely trigonous in cross section, the apex contracted gradually or abruptly to the beak, the apical teeth sharp, 0.5–3 mm long, base subcuneate to obtuse. Flowers unisexual. Corolla (petals) absent. Ovary superior; style 1–2 mm long, the base continuous to the achene apex without any thickening; stigmas 3.

Fruit: Achenes rhombic–ellipsoid; trigonous; without conspicuous constrictions at angles. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Known from a single collection from Moanalua Valley.

Elevation Range: 360–370 m.