324. Carex wahuensis C. A. Meyer subsp. robusta (Franchet & Savatier) T. Koyama, Fl. Taiwan. 5: 326. 1978.
健壮薹草 jian zhuang tai cao
Carex bongardii Boott var. robusta Franchet & Savatier, Enum. Pl. Jap. 2: 561. 1878; C. bongardii Boott; C. boottiana Hooker & Arnott; C. reflexistyla Hayata; C. wahuensis var. robusta (Franchet & Savatier) Franchet & Savatier.
Densely tufted with thick rhizomes; rhizome oblique, clothed with dusty brown fibers. Culms 1 or few to a clump, erect or obliquely ascending, 20-100 cm tall, 1-2 mm thick, trigonous, rigid, scabrous on upper angles. Leaves surpassing culm, blades broadly linear, 3-12 mm wide, flattish, leathery, stiff, sheaths rather short, pale with brown or purple-brown veins, eventually disintegrating into dusty brown parallel fibers. Lower involucral bracts long sheathing, blades leaflike, much surpassing subtending spike but shorter than inflorescence, upper involucral bracts shortly sheathing with short setaceous blade. Spikes 3-6, upper 2 or 3 approximate, remaining spikes distant, or all distant; terminal spike male, narrowly clavate or subcylindric, 3-7 × 3-6 mm; lateral spikes usually female, occasionally becoming androgynous with male part up to 1/2 length of spike, 2-6 × 0.6-0.8 mm, densely many flowered, with erect peduncles. Female glumes pale or slightly rusty brown, ovate or lanceolate-ovate, 4-5 mm, membranous, margins white hyaline, light green 3-veined costa excurrent into a ± straight awn to ca. 5 mm, apex obtuse or shallowly emarginate. Utricles equaling glume, patent, ovate-globose, swollen trigonous, 5-6 mm, herbaceous, glabrous, many veined, contracted at both ends, apical beak erect, spinulose margined, orifice deeply 2-lobed, with sharp curved teeth 1-2 mm. Nutlets rather tightly enveloped, broadly obovoid, trigonous with angles shallowly constricted at middle, crowned with a beak subannulate at base; style base enlarged; stigmas 3, elongate, ± persistent.
Seacoasts, in stable sands and among rocks. Hong Kong, Taiwan [Japan (including Bonin Islands and Ryukyu Islands), Korea].
Carex wahuensis subsp. wahuensis occurs in the Pacific islands (Hawaiian Islands).