Sporadanthus ferrugineus

Detailed description

Robust, dioecious perennial, 1–6 m high, forming dense rafts. Rhizome 10–15 mm diameter, horizontal, branched. Roots 3–5 × 250–300 mm, white. Culms up to 6 m tall, 10–15 mm diameter, brittle, rigid, upright, terete to subterete, smooth or slightly grooved, glaucous green when young, maturing red-brown or yellow-brown; branched in upper ⅔; branches numerous, slender, firm, flexible, upright; basal 140–200 mm of culm conspicuously swollen with soft, spongy, light brown tissue. Culm base with 3–7 loosely appressed, overlapping scales; scales 10–50 × 15–40 mm, ovate to broadly ovate, coriaceous, light brown to brown, apex rounded and mucronate. Leaves along culm solitary, distant, tightly appressed; lamina 15–50 × 15–50 mm, ovate to broadly ovate, brown to dark brown, fading to grey; basal leaves pectinate, upper leaf margins entire or fractured; apex rounded, mucronate. Inflorescence a terminal panicle up to 150 mm long , red-brown, upright to spreading, sometimes drooping; male inflorescence dense, crowded; female inflorescence sparse, diffuse. Flowers pedicellate to almost sessile. Tepals 6, in 2 whorls of 3, 2.0–3.0 × 0.4–0.5 mm, subulate to lanceolate, light brown to yellow-brown, channelled, apex acute to weakly acuminate, mucronate. Stipe 0.6–0.8 mm long. Male flowers with 3 stamens; filaments 1.8–2 .0 mm long, anthers 1.0–1.3 × 0.2–0.4 mm, cream, pollen yellow; pistil rudimentary. Female flowers with 1 pistil; style 0.8–1 .3 mm long, pink, papillose on upper surface, decurrent with ovary on lower surface; ovary 0.3–0.7 × 0.2–0.6 mm, ± globose, amber to dark brown, vertical groove on upper surface; staminodes 3, each 0.5–0.8 mm long. Fruit 1.2–1.5 × 0.5–0.7 mm, narrowly ellipsoid, sides dark brown, suture light brown to cream-brown, surmounted by persistent, long style; dehiscing along lower suture. Seed 0.7–0.8 × 0.5–0.6 mm, shortly oblong to broadly ovate, light orange-brown when fresh fading to light brown.