Rhynchospora rubra (Lour.) Makino APNI*
Description: Slender, shortly rhizomatous perennial.
Culms trigonous, or triquetrous above, nodeless, smooth, 25–100 cm high, 1–2.5 mm diam.
Leaves basal, 2–3(-5) mm wide. Inflorescence globose, dense, 1–1.5 cm diam.; involucral bracts 4–8, rigid, unequal, spreading, finally reflexed, exceeding inflorescence, to 7.5 cm long. Spikelets compressed, 2–4-flowered, 5–8 mm long; lower flower female (very rarely with a single stamen), upper one(s) male. Glumes 6–8, red-brown, distichous, keeled, acute or mucronulate, glabrous; nut-bearing one c. 6 mm long, c. 2 mm longer than the next lower one. Bristles in female flower 3–6, thin, whitish, often ciliate or shortly plumose at base, usually shorter than nut, in the lowest male flower 0–3, absent from other flowers. Stamens (2 or) 3; anthers 1.8–3 mm long. Style shortly 2-fid; style base shortly pyramidal, broader than high, suddenly dilated at base, much narrower than nut (c. 0.5 mm wide). flowers. Stamens (2 or) 3; anthers 1.8–3 mm long. Style shortly 2-fid; style base shortly pyramidal, broader than high, suddenly dilated at base, much narrower than nut (c. 0.5 mm wide).
Nut broad-obovoid, laterally compressed, 1.2–1.8 mm long, 1.0–1.5 mm wide, dark red-brown, minutely reticulate, hispid at apex (rarely all over).
Distribution and occurrence: Coast north from Byron Bay. Also in Qld, NT, WA; Malesia, India to Pacific.
Grows on seasonally flooded flats on sandy soils.
NSW subdivisions: NC
Other Australian states: Qld W.A. N.T.
Text by K. L. Wilson (1993); edited KL Wilson (Jan 2023)
Taxon concept: Flora of NSW 4 (1993)
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