Description

Key Characters:

Growth Form: Tall perennials with woody, erect to spreading rhizomes.

Stems: culms 120–160 cm tall, 5–10 mm in diameter in lower part, terete (cylindrical), smooth, 4–6–nodose between the base and and the inflorescence.

Roots: Fibrous root system.

Leaves: Leaves simple. Leaves numerous, basal and cauline. Blades coriaceous, linear, slightly shorter than or longer than the culm, 7–15 mm wide. Apex gradually attenuate and long caudate-acuminate. Margins involute, serrulate–scabrous. Veins parallel. Sheathing; basal sheaths dark purplish brown or dusky brown, the cauline sheaths green, tinged with purplish brown toward base. Stipules absent.

Flowers: Flowers in inflorescence a large, effuse, decompound panicle 30–90 cm long, 5–15 cm wide, densely branched, bearing numerous spikelets, sometimes slightly interrupted in lower part, leafy bracts narrowly linear or the upper ones subsetaceous, usually slightly shorter than the inflorescence, the sheathing base dark purplish brown, 2–5 cm long, peduncles 2– 4 together, branched, bracteoles black, spathaceous; spikelets solitary, oblanceoloid to obovoid in fruit, 2–3.5 mm long, ca. 2 mm wide, 1–flowered; glumes 4–5, the lower 1–2 dark brown, membranous, ovate, 2.5–3 mm long, acuminate and short-awned at apex, equaling to slightly longer than the 3 upper glumes, 1–nerved, the 3 upper glumes blackish brown, ovate, obtuse or mucronate, ca. 2 mm long. Flowers bisexual (perfect) or staminate. Calyx (sepals) absent. Corolla (petals) absent. Stamens 3. filaments ca. 10 mm or more long strongly flexuous or crisped. Ovary superior; styles elongate, the base conical–subulate, persistent at achene apex.

Fruit: Achenes yellowish brown; eventually turning blackish brown; glossy; obovoid–ellipsoid; trigonous; 1.7–2.6 mm long; 1–1.5 mm wide. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Occurring in open sites in wet forest and margins of bogs; vicinity of Alaka'i Swamp to Mount Wai'ale'ale.

Elevation Range: 610–1,590 m.