稻形珍珠茅 dao xing zhen zhu mao

Scleria oryzoides J. Presl & C. Presl.

Perennials. Culms to 1 m tall, robust, 3-angled, scabrous, glabrous. Leaf sheath 7-25 cm, to 2 mm thick, leathery to ± fleshy, glabrous, sometimes 3-winged, basal ones purplish red; contraligule not prominent; leaf blade linear, ca. 1 m × 1-2.5 cm, glabrous, margins sometimes scabrous, apex acute. Involucral bracts setaceous, basalmost to 1.5 cm; bractlets glumelike, shorter than spikelets. Inflorescences compound paniculate, ca. 15 × 7-8 cm, with many branches; branch axes long, angled, scabrous, with many spikelets. Spikelets 1 or 2 in a cluster, dark brown, unisexual. Male spikelets many, more than female ones, oblong-ovoid, ca. 4 mm, apex truncate; glumes 2-3 mm, membranous, with rust-colored lines. Female spikelets usually at base of branch, narrowly ovoid, slightly longer than male ones, apex acuminate; glumes triangular-ovate, ovate-lanceolate, or broadly ovate, slightly longer than male glumes. Male flowers: stamen 1; anther linear, ca. 1.7 mm; connective apex protruding, 1/5-1/4 as long as anthers. Female flowers: stigmas 3. Disk brown, triangular-cordate, ca. 1.5 mm in diam., 3-lobed; lobes triangular, short, margin reflexed, apex acute. Nutlet white or gray, ovoid, ca. 3 × 2.5 mm, bluntly triangular, smooth, shiny, glabrous. Fl. and fr. Apr.

Water margins. Hainan [Cambodia, India, Indonesia, Laos, Malaysia, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; tropical Africa and Australia, Madagascar].