c, e North America, Mexico, West Indies, Central America, South America, Africa, se Asia, India, n Australia, pantropical.
Genera ca. 50, species ca. 260 (1 in the flora).
Molecular evidence indicates that Podostemaceae is related to Clusiaceae within the Malpighiales (M. H. G. Gustafsson et al. 2002). Structural modifications of vegetative features has led to controversy regarding how best to interpret the structural categories of root, shoot, and leaf in Podostemaceae (for example, I. Jäger-Zürn 2005; R. Rutishauser 1997).
Jäger-Zürn, I. 2005. Morphology and morphogenesis of ensiform leaves, syndesmy of shoots and an understanding of the thalloid plant body in species of Apinagia, Mourera and Marathrum (Podostemaceae). Bot. J. Linn. Soc. 147: 47–71.