Eriocaulon inapertum G.J.Leach

Herb 10–23 (–30) cm high. Leaves linear, 2–6 cm long, 1.7–4 mm wide, 4–10-nerved. Peduncle 12.5–21 cm long. Sheath 25–35 mm long. Flower heads hemispherical or globular, 3–5.5 mm long, 4–5.5 mm wide. Involucral bracts straw-yellow, obovate, 2–2.5 mm long, 0.8–1.75 mm wide, obtuse, glabrous, strongly reflexed at maturity. Floral bracts hyaline, oblanceolate, 2–2.75 mm long, 0.9–1.6 mm wide, acuminate, pubescent with white hairs. Receptacle densely pilose. Male flowers: sepals 3, fused but split on one side to form a spathe with spathe margins overlapping and appearing as a tube, hyaline, 1.3–1.55 mm long, 0.75 mm wide, truncate, pubescent with sparse scattered white hairs; petals 3, sometimes obscure, hyaline, equal or dimorphic with one larger and prominent, obtuse, pubescent with apical fringe of white hairs or glabrous; stamens 6; anthers black. Female flowers: sepals 2–3, hyaline or straw yellow, dimorphic, laterals navicular, with broad, rarely narrow dorsal wing, 1–1.7 mm long, 0.5–0.7 mm wide, crested, pubescent with sparse white hairs along crest and upper margin, hyaline hairs inside orifice; median sepal linear, hyaline, sometimes obscure amongst receptacle hairs, 0.9–1.2 mm long, c. 0.01 mm wide, acute, glabrous; petals 3, hyaline, equal or slightly dimorphic with one slightly larger, linear to narrowly elliptic, 1.2–1.4 mm long, 0.13–0.27 mm wide, acute, pubescent with white hairs in apical fringe and on margins; ovary 3–locular. Seeds 0.4–0.45 mm long, 0.275–0.33 mm wide; epidermal cell wall thickenings as continuous bands on transverse walls.

In the Northern Territory typically associated with sandstone ranges; open grass or sedge swamps associated with seepage areas. In shallow water to 20 cm deep. In the Kimberley associated with organic mound springs in black peaty clay in sedgeland.