疏松珍珠茅 shu song zhen zhu mao

Scleria trisulcata G. P. Li.

Annuals. Roots fibrous. Rhizomes short or not well developed, thick. Culms tufted, 20-40 cm tall, slender, 3-angled, smooth, glabrous, apically often nodding. Leaves cauline; sheaths at culm base glabrous, barely winged, bladeless or with a short blade; sheaths at middle and apical part of culm narrowly winged, villous and more densely so near contraligules; contraligule semicircular, apex obtuse; leaf blade linear, 3.5-5.5 mm wide but apically attenuate, papery, both surfaces hairy or only on 2 lateral veins of abaxial surface, margins scabrous, apex slightly obtuse to acute. Involucral bracts leaflike, sheathing, opening of sheath with dense brown pubescence; bractlets setaceous, as long as or slightly longer than spikelet. Inflorescences paniculate, with 2-4 branches; branches 1.2-3 cm, distant, with few spikelets. Spikelets narrowly ovoid, 4-5 mm, mostly unisexual; female spikelets with 4 or 5 glumes and 1 female flower; male spikelets with 7-9 or more glumes. Glumes deeply straw-colored to brownish purplish, ovate to lanceolate, keeled, apex acute and apiculate. Male flowers: stamens 2 or 3. Female flowers: ovary subspherical, glabrous. Disk yellowish white, 1/4-1/3 height of nutlet, slightly 3-lobed; lobes ovoid-triangular to subglobose, margin reflexed, apex truncate. Nutlet subspherical to obovoid-spherical, 2.8-3 × 1.8-2 mm, trisulcate, pitted with irregular longitudinally elongate lacunae (i.e., trabeculate), glabrous, apex with a yellowish white tip. Fl. and fr. Aug-Oct.

Grassy swamps; near sea level. Fujian (Zhao’an), Guangdong, Hainan [Papua New Guinea, Philippines; N Australia].