Podostemaceae

Riverweed family
Mourera fluviatilis
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Malpighiales
Family:	Podostemaceae Rich. ex Kunth
Genera
About 50; see text

About 50; see text

Podostemaceae (riverweed family) is a family in the order Malpighiales. It comprises about 46 genera and ca 300 species of more or less thalloid aquatic herbs.

Riverweeds adhere to hard surfaces (generally rock) in rapids and waterfalls of rivers. They are found mostly in tropical and subtropical areas worldwide. Many species are found in a very small geographic area (perhaps even just a single river or waterfall). Riverweeds are submerged when water levels are high, but during the dry season they live a terrestrial existence, flowering at this time. Their root anatomy is specialized for the purpose of clinging to rocks, and in fact details of the root structure are one of the ways of classifying riverweeds.

The Podostemaceae are related to the families Clusiaceae, Hypericaceae (the St. John's wort family, which is sometimes treated as a subfamily of Clusiaceae), and Bonnetiaceae. In the classification system of Dahlgren Podostemaceae were placed as a single family in the Podostemales order, which was the only order in the superorder Podostemiflorae (also called Podostemanae).

Eugenius Warming, a botanist who studied the family

Masahiro Kato, The vague form created by the environment: Podostemaceae, Biohistory Journal, Spring, 2004.

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Wikipedia