Petrea Linnaeus (1753: 626)

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 : 24

8. Petrea Linnaeus (1753: 626) .

Lianas, monoecious, branches without prickles, not aromatic. Leaves petiolate, glands near to the petiole absent. Inflorescences axillary, simple, racemes spiciform; rachis elongated; bracts membranaceous, lilac; bracteoles absent. Flowers pedicellate; calyx tubular, petaloid, longer than the corolla, membranaceous, purple or lilac, 5-lobed, lobes obtuse, persistent, accrescent in fruit; corolla zygomorphic, 5-lobed; stamens 4, included, didynamous, superior pair without connective appendages, thecae introrse; ovary 1-carpelate, 2-loculate, ovules 1 per locule, stigma obliques. Fruit drupe, with 2 pyrenes, brown, external surface striate in the base, rugose toward the apex.

Petrea is part of the tribe Petreeae ( Marx et al. 2010) and presents 12 species distributed from the South of Mexico to Argentina, with most of the richness concentrated in the Amazon Forest ( Rueda 1994, Marx et al. 2010, Cardoso et al. in press.). The genus is characterized by the presence of a calyx longer than the corolla, protecting it in the pre-formation, as well as the ovary after the senescence of the corolla, also attracting pollinators and aiding the fruit dispersal ( Rueda 1994). Eight species occur in Brazil, of which three are endemic, and two are found in the Atlantic Forest ( Cardoso & Salimena 2020a). There is one species in Espírito Santo.