Thurniaceae

Abstract

Coarse perennial herbs from an upright roostock. Leaves tristichously arranged, simple, parallel-veined, all basal, with sheathing base and elongate, leathery, flat or (in cross-section) V-shaped, sometimes prickly margined blade. Inflorescences of one or more dense, racemose, globose to ellipsoid heads subtended by spreading, leafy bracts on an otherwise leafless, bluntly triangular or quadrangular peduncle; flowers perfect, regular; pedicel short, swollen, spreadingly puberulous, grading into the perigone; tepals persistent, chaffy, 3 + 3 equal, spotted; stamens distinct, 3 + 3, with the filaments somewhat adnate to the base of the tepals; anthers basifixed, tetrasporangiate, introrse, opening by longitudinal slits; pollen borne in tetrads, scabrate and ulcerate; gynoecium of 3 carpels united to form a compound, superior, trilocular pistil with 3 or more erect, anatropous, crassinucellar, ascending ovules; ovary tapering distally, scarcely produced into a style, with 3 elongated stylodia, stigmas dry. Fruit a loculicidal capsule, commonly with 3 spindle-shaped seeds supplied at each end with a hispid process, 1 in each locule; embryo small, cylindric, monocotyledonous, embedded in copious, mealy, starchy endosperm.