21. Carex rafflesiana Boott, Trans. Linn. Soc. London. 20: 132. 1846.
红头薹草 hong tou tai cao
Carex bengalensis Roxburgh var. scaberrima Boeckeler; C. cruciata Wahlenberg var. rafflesiana (Boott) Nooteboom; C. rafflesiana subsp. scaberrima (Boeckeler) T. Koyama; C. rafflesiana var. scaberrima (Boeckeler) Kükenthal; C. scaberrima (Boeckeler) C. B. Clarke.
Rhizome short, subwoody. Culms tufted or single, 80-200 × 0.3-0.5 cm, trigonous, smooth, base covered by 1 or 2 reddish brown sheaths. Leaves shorter than culms, flat, 10-13 mm wide; sheaths long, reddish brown; persistent sheaths fibriform. Involucral bracts leafy, long sheathed, lowest one as long as or longer than inflorescence, upper ones gradually shorter. Panicle compound, ca. 20 cm, 8-11-branched; inflorescence branches usually binate, oblong-lanceolate, 5-15 cm, slightly dense, lower part branched. Spikes numerous, bisexual, androgynous, arising from cladoprophylls, ovate-oblong, 3-6 mm; male part of spike nearly as long as female part; female glumes white with reddish brown spots, ovate or ovate-lanceolate, 1.5-2 mm, scabrid, midrib extending into mucro, apex obtuse or acute. Utricles reddish brown, oblong or elliptic-oblong, trigonous, 2.7-3.5 mm, herbaceous, with several veins, upper part hairy, apex attenuate into beak, beak excurved, nearly as long as utricle body, orifice minutely 2-toothed. Nutlets elliptic, trigonous, ca. 1.5 mm; style base not thickened; stigmas 3.
Forest margins, grasslands on slopes; 500-600 m. Taiwan [Indonesia, Malaysia, Philippines, Thailand; Australia].