Description from Flora of China
Herbs perennial, sometimes subshrubby, evergreen. Rhizome generally branched, stout. Stem simple or branched. Leaves sub-basal, distichous, basally often equitant, grasslike, rigid, midvein raised abaxially. Scape usually relatively tall, to 2 m, with few linear-lanceolate cauline leaves and a terminal panicle. Panicle laxly branched, usually large, with several to many racemes or smaller panicles; bracts rather small. Flowers usually nodding, rather small; pedicel articulate apically. Tepals 6, free, 3--7-veined. Stamens 6, inserted at base of tepals; filaments thickened; anthers basifixed, dehiscing by terminal pores. Ovary 3-loculed; ovules 4--8 per locule. Style slender; stigma small. Fruit a berry. Seeds black, often flattened.
Although Clifford et al. (in Kubitzki, Fam. Gen. Vasc. Pl. 3: 251. 1998) placed Dianella in the Hemerocallidaceae, Wu Zhengyi (editor’s note) believes it should be treated in the segregate family Phormiaceae. Takhtajan (Diversity Classific. Fl. Pl. 512. 1997) recognized Phormiaceae but placed Dianella in the Dianellaceae.
About 20 species: mainly in tropical Asia, also in Africa (Madagascar), Australia, and Pacific Islands; one species in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Minoru N. Tamura)