Species commonly cultivated
Hydrotriche hottoniiflora Zucc. (Madagascar)
Perennial or annual. Stems mostly erect or creeping, elongate, delicate, rarely branching. Leaves relatively evenly spaced along stem in whorls of 10-20, sessile, linear to lanceolate; margin entire but serrulate apically. Inflorescence an erect raceme of 2-5 flowers; pedicels present or absent. Flowers weakly zygomorphic; sepals 5; corolla tubular, 2-lipped, lobes subequal; adaxial lip 2-lobed, abaxial lip 3- lobed, white, blue, pink or yellow. Dispersal by stem fragments and possibly seed.
found in both still and fast flowing water