苏里南莎草 su li nan suo cao

Annuals (?or short-lived perennials). Rhizomes absent. Culms tufted, (10-)35-80 cm tall, 3-angled, scaberulose with retrorse prickles. Leaves shorter than culm, flat or V-shaped; leaf blade 5-8(-12) mm wide. Involucral bracts 3-8, horizontal to ascending at ca. 30°, 3-30(-50) cm × 1.5-8(-12) mm, flat or sometimes V-shaped. Inflorescences globose heads, 1-2 cm in diam.; rays 4-12, 1-6(-9) cm, scaberulose with retrorse prickles; raylets often present. Spikelets (6-)15-40(-65), linear to linear-oblong, 4-12 × 1.5-2.5 mm, compressed. Glumes 10-50, pale yellow, light brown, or reddish brown, lanceolate, 1-1.5 mm, medially 3-veined, laterally veinless but distinctly reticulate, basally 2-keeled, apically often scaberulose, apex mucronulate. Stamen 1; anthers ca. 0.5 mm. Nutlets slightly stipitate, brown to reddish brown, narrowly ellipsoid, 0.7-0.9 mm, 3-sided, papillate or obscurely reticulate to rugulose, apex apiculate. Fl. and fr. Mar-Sep.

Pond shores, roadsides; below 200 m. Naturalized in N Taiwan [native to Caribbean and Central, North, and South America].

Cyperus surinamensis is also naturalized in Indonesia (Borneo).