Xyris bicarinata Griseb.

Xyris bicarinata Griseb. Cat. PI. Cub. 223. 1866
Xyris cubana A. Nilsson. Sv. Vet.-Akad. Handl. 24 14 : 27. 1892. Xyris navicular is var. abbreviate, Malme, Ark. Bot. 13 s : 16. 1913. Xyris bicarinata var. abbreviata Malme, Ark. Bot. 19 19 : 4. 1925.
Perennial, densely tufted; leaves narrowly linear, 15-20 cm. long, 1-1.5 mm. broad, often spirally twisted, acute, smooth or somewhat scabrid beneath, with thickened margins; sheath occupying one sixth to one fifth the length of the leaf, tuberculate-scabrid, dark-chestnutcolored below, much dilated at the base; peduncles usually 30-40 cm. tall, about 0.75 mm. broad, terete or nearly so, bicostate, scabrid on the ridges, elsewhere smooth, the peduncular sheath 5-7 cm. long, chestnut-colored and slightly shining beneath; spike few-flowered, obovoid or ellipsoid, 7-9 mm. long, 3-4.5 mm. thick, the outer barren bracts ovate-elliptic, about 2.5 mm. long, obtuse or rounded at apex, the flowering bracts elliptic, 5-6 mm. long, about 3.5 mm. broad, rounded at the apex or nearly so, entire, ecarinate, pale-rusty, with a rather indistinct elliptic somewhat rusty dorsal area; lateral sepals included, lanceolate, about 5 mm. long, 1-1.25 mm. broad, acute: keel narrow, serrulate-ciliate toward the apex; seeds oblong-ellipsoid, 6 mm. long.
Type locality: [Pinar del Rio], western Cuba. Distribution: Western Cuba and Isla de Pinos.