Evidence for a Polyphyletic Origin of the Labiatae

A preliminary cladistic analysis suggests that the Labiatae are polyphyletic as presently circumscribed. The gynobasic-styled Labiatae emerge as a clade, nested within a larger group characterized by suprareticulate pollen and a fruit composed of nutlets. The latter includes the bulk of the Labiatae plus the verbenaceous genera Garrettia and Holmskioldia; its closest relatives are in tribe Viticeae (Verbenaceae). In contrast, Teucrium and five other genera of Ajugeae (Labiatae) belong to a large clade characterized by pollen with branched to granular columellae, most members of which are currently assigned to tribes Clerodendrea and Caryopterideae (Verbenaceae) (...)