Two new synonyms in Heteranthera (Pontederiaceae, Commelinales)

Hydrothrix and Scholleropsis, two segregate monospecific genera placed within the Heteranthera s.l. clade, are here transferred to Heteranthera based on phylogenetic and morphological data. A brief discussion on the morphology and affinities of Heteranthera s.l. is given, along with the designation of lectotypes for the two new transfers.