Cottsia is a small genus of flowering plants in the family Malpighiaceae, within the order Malpighiales. The family comprises roughly 75 genera of mostly tropical and subtropical vines, shrubs, and trees, many of which — like Cottsia — are twining lianas.
Cottsia comprises three species of slender, twining vines. Their native range centers on northern Mexico and extends north into the southwestern United States, including Texas, New Mexico, and Arizona, placing the genus at the northern edge of the largely Neotropical family.
The genus name Cottsia was published by Dubard & Dop in 1908 (Revis. Gen. Pl. Bot. 20: 359), but for much of the 20th century its species were treated as part of Janusia, a related Malpighiaceae genus centered in South America. A 2007 generic revision of Neotropical Malpighiaceae by Anderson & Davis (Contributions from the University of Michigan Herbarium 25: 137–166) resurrected Cottsia as the correct genus for these northern, Mexican/southwestern-U.S. species, separating them from the more southerly Janusia. The single species represented in this database, Cottsia gracilis ("Slender Janusia"), still carries the older generic epithet in its common name, a reminder of this relatively recent reclassification.
Distribution
Cottsia is native to northern Mexico and extends into the southwestern United States (Texas, New Mexico, and Arizona).
Taxonomy Notes
Cottsia was described by Dubard & Dop in 1908. Its species were long included in the South American genus Janusia until Anderson & Davis's 2007 generic revision of Neotropical Malpighiaceae reinstated Cottsia for the northern Mexico/southwestern-U.S. species. GBIF records 3 accepted species in the genus, matching the count given by Wikipedia.
