Polycarpon, Syst. Nat., ed. 10 2: 859, 881, 1360. 1759 sec. Kool & al. (2007)
- Type: Polycarpon tetraphyllum
Monotypic; Mediterranean and western North America. Kool & al. (2007) found Polycarpon was polyphyletic with species distributed in three clades. Two of these included species of Polycarpaea and were removed from Polycarpon. The third included members of the P. tetraphyllum group; tight relations in the remaining clade suggested reduction to one polymorphic species.