Saturday, July 6, 2024

[Botany • 2024] Eugenia guapiassuana (Myrtaceae) • A remarkable New tree Species from the Brazilian Atlantic Forest


 Eugenia guapiassuana  T.Fern., M.T.C.Lacerda & J.M.A.Braga, 

 in Fernandes, Prieto, Lacerda, Bünger et Braga, 2024. 

Summary
This study proposes a new species of Eugenia sect. Phyllocalyx from Atlantic Forest remnants in the Brazilian state of Rio de Janeiro. The new taxon, Eugenia guapiassuana, is proposed based on literature survey, examination of herbarium material and field work. We herein provide a morphological description, including comments on fruit taste, along with information on distribution, habitat, phenology, vernacular name, taxonomy and conservation status. Figures showing fresh and dry material and a map of the occurrence records are also presented. Eugenia guapiassuana is morphologically similar to E. involucrata and E. superba, and these species are contrasted in the discussion. Following an assessment, the conservation status of Eugenia guapiassuana is provisionally determined as Critically Endangered [CR B2ab(iii)].

Key Words: Cereja-de-guapiaçu, Eugenia sect. Phyllocalyx, fruit tree, Reserva Ecológica de Guapiaçu, threatened species

Morphology of Eugenia guapiassuana.
A leaf adaxial surfaces with puberulent indument; B leaf abaxial surface; C leafy shoots, adaxially cinereous, sericeous, abaxially glabrous and vinaceous; D inflorescences developing along with leafy shoots; E flower bud at early stages of development; F pre-anthetic flower; G flowers at anthesis; H flower from below, showing the cordiform bracteoles; J post-anthetic flower, after stamens fall; K detail of the thick, verrucose pedicel in fruit, swollen at base and apex; L mature fruit with persistent trichomes concentrated on the transition with the calyx (arrowed); M mature fruits.
A – J from Fernandes 1218; K – M from Fernandes 1268. Phtots: Thiago Fernandes.

Eugenia guapiassuana T.Fern., M.T.C.Lacerda & J.M.A.Braga sp. nov. 

ETYMOLOGY. The epithet is a tribute to Reserva Ecológica de Guapiaçu (REGUA), an outstandingly important area for the conservation of Atlantic Forest biodiversity, close to which the new species was found. Guapiaçu (latinised Guapiassu) is treated as an institutional name and adjectivised as guapiassuana. The Tupi indigenous word Guapiaçu (= large headwaters) is the name of the main river crossing the Reserve.


Thiago Fernandes, Pablo Viany Prieto, Marco Túlio Côrtes de Lacerda, Mariana Bünger and João Marcelo Alvarenga Braga. 2024. Eugenia guapiassuana (Myrtaceae), A remarkable New tree Species from the Brazilian Atlantic Forest.  Kew Bulletin. 79; 233–241. DOI: doi.org/10.1007/s12225-023-10159-z