6. Rhynchospora gracillima Thwaites, Enum. Pl. Zeyl. 435. 1864.
柔弱刺子莞 rou ruo ci zi guan
Rhynchospora kamphoeveneri Boeckeler.
Annuals or short-lived perennials. Culms densely tufted, 20-60 cm tall, filiform, 3-angled, smooth. Leaves shorter than culm; leaf blade setaceous, 0.5-1 mm wide, canaliculate, apex scabrous. Involucral bracts setaceous, sheathing. Inflorescences laxly paniculate, consisting of 1-3 corymbiform anthelae to 4 cm; terminal anthela longer than lateral ones, simple or subcompound; lateral anthelae simple, with peduncles exserted from sheaths; rays capillary, 2-4 cm, often upcurved, smooth, subtended by setaceous bractlets. Spikelets solitary, narrowly ovoid, 3- or 4-flowered, apex acute; peduncle long. Glumes 7 or 8, pale rust-colored with purplish lines, spirally imbricate, broadly ovate, membranous, muticous. Perianth bristles absent. Stamens 2; anthers 1.5-2.3 mm. Style ca. 2.3 mm, base much depressed, saddle-shaped, 2-lobed, and almost as broad as nutlet, apex 2-cleft to middle. Nutlet grayish white, shortly stipitate, broadly obovoid, 1.3-1.5 × 1.3-1.5 mm, biconvex, deeply transversely wavy ridged, with longitudinally linear epidermal cells, apex truncate. Fl. and fr. Sep-Oct.
Moist places, grassy slopes, forests; 900-1000 m. Fujian, Hong Kong [India, Indonesia, Papua New Guinea, Sri Lanka, Thailand; tropical Africa, NE Australia, Indian Ocean islands, Madagascar].
No specimens of Rhynchospora gracillima from China have been seen by the present authors. The plants from China would be R. gracillima subsp. gracillima; another subspecies occurs in tropical Africa and Madagascar.