Petrea, Linnaeus, 1753

Cardoso, Pedro Henrique, Valério, Vanessa Imaculada Dos Reis, Neto, Luiz Menini & Salimena, Fátima Regina Gonçalves, 2021, Verbenaceae in Espírito Santo, Brazil: richness, patterns of geographic distribution and conservation, Phytotaxa 484 (1), pp. 1-43 : 7

1. Calyx purple or lilac, longer than the corolla........................................................................................................................ 8. Petrea

1’. Calyx green, shorter than the corolla.