Description from Flora of China
Herbs, very rarely shrublike, perennial or annual, tufted or with erect or creeping rhizome. Stems erect, terete or laterally flattened. Leaves occasionally reduced to a bladeless or nearly bladeless sheath at base of stem (cataphyll); leaf sheath often shortly prolonged on both sides into a pair of auricles at leaf blade juncture; leaf blade of basal and cauline leaves usually linear or filiform, grasslike and flat, or terete, glabrous except for pilose margin on some grasslike blades. Inflorescence a panicle, corymb, or 1-flowered. Flowers bisexual or unisexual and plants dioecious, mostly wind pollinated, regular, usually small, usually 1- or 2-bracteolate at base. Perianth segments (3 or)6, in (1 or)2 whorls, free, usually greenish to brownish or blackish, rarely white or yellowish, glumelike. Stamens 3 or 6, if 6 then 3 opposite outer perianth segments; filaments thin; anthers basifixed, 2-loculed, dehiscing by longitudinal slits; pollen grains in tetrads. Ovary superior, 1-loculed, or divided by 3 septa and 3-loculed, or incompletely septate; ovules 3 and inserted at base of ovary, or numerous and biseriate on 3 parietal placentas. Stigmas 3, papillose. Fruit a capsule, 1--3-valved, loculicidal. Seeds globose, ovoid, or fusiform, small, sometimes appendaged; appendage caudate; embryo straight, minute, enclosed by fleshy endosperm.
Wu Kuo-fang. 1997. Juncaceae. In: Wu Kuo-fang, ed., Fl. Reipubl. Popularis Sin. 13(3): 146--253.
About eight genera and ca. 400 species: widely distributed in temperate and cold regions of both hemispheres, in tropical regions restricted to high elevations; two genera and 92 species (33 endemic) in China.
(Authors: Wu Guofang (吴国芳 Wu Kuo-fang); Steven E. Clemants)