生活型

herb

形態特徵

• Tufted in small clumps with fibrous roots. Culms slender, 7-30 cm tall, 1-1.7 mm thick, trigonous, greenish, clothed at base with 2 or 3 sheaths only.
• Sheaths 5-15 cm long, membranaceous, pale green, orifice obliquely truncate with a mucro 2-4 mm long, frequently uppermost sheath borne 1-2 cm above base of culm, this sometimes developing a compressed, triangular blade to 10 cm long.
• Inflorescence pseudo-lateral, head-like or corymbose with to 4 short (0.5-3 cm long) rays; bract(s) 1 or 2, first bract erect, 3-12 cm long, ventrally sulcate, second bract, when present, patent, 2-4 cm long. Spikelets 3 to 20 to an inflorescence, wholly congested or clustered in groups of 2 to 7 at apices of rays, lanceolate-ovate to oblong, 4-8 mm long, 2-3 mm wide, pale-green and becoming light straw colored, subdensely manyflowered, subacute at apex.
• Glumes elliptic, 1.8-2.5 mm long, boat shaped with a prominent, green, 3-nerved keel, both sides membranaceous, pale with often sanguineous spots, contracted above to mucronate apex. Achenes broadly obovate, 1-1.3 mm long, truly triangular, suddenly contracted at both ends, mucronate at apex, sides transversely wrinkled, maturing black; style 1.5 cm long, 3-cleft at apex. Hypogynous bristles 0, rarely rudimentally.

分布

• 台灣 : Wet places, frequently in rice fields.
• 世界 : Tropical and subtropical Asia and Australia.

引證標本

MIAOLI: Chunan, Shimada 683. PINGTUNG: Ako, Nakahara 510 (TI, type of S. erecto-gracilis; Manchou, Hsu 13072*. Shimotamsui, Shimada (KYO) KAOHSIUNG: Kaohsiung, Shimada 4471. Rokki in Kaohsiung Hsien. Okamoto.

參考文獻

• KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao, Flora of Taiwan, second edition 5: 191. 2000.  (Fl. Taiwan 2nd edit.)