Description from Flora of China
Herbs perennial, rhizomatous, sympodial, usually terrestrial, rarely epiphytic. Stem erect, arching, or sometimes ± scandent, simple. Leaves cauline, lateral and pseudoterminal, alternate, opposite, or whorled, sessile or shortly petiolate, sometimes cirrose at apex. Inflorescences axillary, umbel-, corymb-, or racemelike, or a solitary flower; bracts present or absent, when present herbaceous, membranous, or scarious, persistent or caducous. Flowers bisexual, usually pendulous, rarely erect; pedicel articulate at apex. Perianth segments 6, valvate, connate proximally and forming a tube usually for at least 1/2 their length. Corona absent. Stamens 6; filaments proximally adnate to perianth tube, free part filiform or flattened, short to long, smooth, papillose or hairy; anthers basifixed to dorsifixed and versatile, introrse, base 2-lobed. Ovary 3-loculed; ovules 2--8 per locule. Style slender; stigma 3-lobed, small. Fruit a berry, globose, several to more than 10-seeded. Seeds subglobose.
About 60 species: temperate regions of the N hemisphere, mainly from the Himalayas to Japan; 39 species (20 endemic) in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Minoru N. Tamura)