Hymenaea mexicana sp. nov. (Leguminosae: Caesalpinioideae) from Mexican amber indicates Old World connections

Hymenaea mexicana sp. nov. is described in amber originating from mines of Chiapas, Mexico. The species is characterized by clawed showy petals with cordate bases and glabrous, verrucose ovaries with long hirsute hairs at their bases and margins on one side. This species is closely related to the extinct Hymenaea protera from Dominican amber, and together with it, is placed in the primitive section Trachylobium of the genus Hymenaea in the caesalpinoid legumes. The closest extant species to H. mexicana is H. verrucosa, a relict surviving in East Africa. These results challenge previous views that Mexican amber was produced by the South American species H. courbaril – H. intermedia, which belong to the advanced section of the genus.