Description from Flora of China
Mariscus pedunculatus (R. Brown) T. Koyama; Miegia maritima (Aublet) Willdenow; Remirea pedunculata R. Brown.
Rhizomes slender, long creeping, branching, rigid. Culms 6-15 cm tall, 1-2 mm thick, 3-angled, smooth, basally clothed with brown sheaths and their fibrous remnants and buried in sand. Leaves 3-15, covering base and lower culm, usually slightly longer than culm; sheath pale brown; leaf blade lanceolate, 4.5-6.5 mm wide, leathery, abaxial surface prominently keeled. Involucral bracts leaflike, longer than inflorescence. Inflorescences terminal, capitate, usually with 2-7 clusters, oblong-ellipsoid to ovoid-oblong, 1-2 × 0.7-1 cm, with many spikelets. Spikelets dense, fusiform-ellipsoid, ca. 5 mm; bractlets glumelike, ovate-lanceolate, ca. 3 mm, with brown lines, 1-veined, apex acute. Basal 3 glumes without a flower; basalmost glume broadly ovate, ca. 2 mm, 2-veined and with brown lines, apex rounded; second glume ovate, ca. 4 mm, 7-veined, apex rounded; third glume slightly longer than second one; fourth glume fleshy, ca. 3 mm, veinless, with brown minute spots, margin involute, apex slender. Stamens 3; anthers ca. 2 mm. Ovary oblong, 3-sided; style short; stigmas 3, slender, ± as long as style. Nutlet blackish brown, sessile, cylindric-ellipsoid, 2-2.5 mm, compressed 3-sided. Fl. and fr. Sep-Dec.
Moist sandy beaches; near sea level. Guangdong, Hainan, Taiwan [India, Indonesia, Japan (Ryukyu Islands), Malaysia, Myanmar, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; tropical Africa and America, N Australia, Indian Ocean islands, Madagascar, SE North America, Pacific islands].