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
Four species are described in this genus, all from Madagascar, but only Hydrotriche hottoniiflora is cultivated for aquaria.