Petenaea

Petenaea cordata (from northern Central America) was first described in Elaeocarpaceae and later placed in Tiliaceae, but most authors have been uncertain about its familial affinities. It was considered a taxon incertae sedis in the Angiosperm Phylogeny Group classification (APG III). Molecular analyses based on a recent collection from Guatemala indicate a distant, weakly supported sister-group relationship to the African genus Gerrardina (Gerrardinaceae; Huerteales). As no obvious synapomorphies exist for Gerrardina and Petenaea, the new monogeneric family Petenaeaceae was proposed. The polymorphic order Huerteales now comprises four small families: Dipentodontaceae, Gerrardinaceae, Petenaeaceae and Tapisciaceae. Petenaea cordata is the only species in the genus Petenaea.