Description from Flora of China
Hexonix Rafinesque, nom. rej.; Kozola Rafinesque, nom. rej.; Sugerokia Miquel.
Herbs perennial, with a short, thickened rhizome, glabrous. Leaves basal, rosulate, narrowly oblong to oblanceolate or obovate, proximally gradually narrowed to a petiole, evergreen, margin smooth, sometimes minutely undulate. Scape arising from center of leaf rosette, erect, simple, hollow, with 2--8 scale leaves. Inflorescence a terminal umbel or umbel-like raceme, 1--10-flowered; bract usually absent. Flowers bisexual, usually slightly nodding at anthesis, ascending in fruit, spreading funnelform. Tepals 6, free, spatulate or linear-oblanceolate to oblong, adaxially often with a deep pocket of a nectary gland at base, persistent. Stamens 6, often adnate basally to tepals, sometimes free, always free from ovary, usually exserted, rarely included; anthers lanceolate, dorsifixed, extrorse to latrorse, sometimes with locules confluent at apex. Ovary superior, 3-loculed; ovules 60--180 per locule. Style 1, slender, rather long; stigma capitate. Fruit a capsule, 3-lobed, loculicidal. Seeds small, linear, both ends caudate.
Tanaka (J. Jap. Bot. 73: 102--115. 1998) reduced Heloniopsis and Ypsilandra to synonymy under Helonias. However, a recent molecular phylogenetic study by Fuse and Tamura (Plant Biol. 2: 1--13. 2000) confirmed that Helonias Heloniopsis and Ypsilandra are not mixed with each other, and they each deserve independent generic status.
Five species: China, Japan, Korea; one species (endemic) in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Minoru N. Tamura)