Eugenia (Myrtaceae) from Reserva Natural Vale, Espírito Santo, a center of plant endemism in the Brazilian Atlantic Rainforest

Abstract

Eugenia includes ca. 1,100 species worldwide and is the richest angiosperm genus of Brazilian flora with a remarkable biodiversity in the Atlantic Rainforest. In Espírito Santo state, the central-north region conserves the biggest forest fragment and is composed by the lowland coastal forests known as Tabuleiro. Considering the scarcity of studies approaching this vegetation and the high diversity of Eugenia species, this work presents a taxonomic treatment of Eugenia species from Reserva Natural Vale. The study area is located at the municipalities of Linhares and Sooretama, in the northern part of the coastal mesoregion of the state. For the taxonomic treatment, fieldwork was carried out between August 2015 and March 2019 and herbarium collections of BHCB, CVRD, CEPEC, ESA, HRCB, HPL, HUFSJ, ICN, K, MBM, MBML, RB, RBR, SORO, SP, SPF, SPSF, UB, UEC, and VIES were consulted, as well as images of nomenclatural types available online. This work points out the occurrence of 48 species of Eugenia within Reserva Natural Vale, encompassing 48% of the Eugenia species recorded in the Espírito Santo state. Six of them are presented as new occurrences for the reserve (Eugenia arenaria, E. disperma, E. florida, E. handroi, E. pachnantha and E. schottiana); two (E. pachnantha and E. schottiana) are first recorded for the state; E. adenophylla and E. infuscata are described as new. Eugenia adenophylla, E. atlantica, Eugenia cataphyllea, E. flavicarpa, E. hispidiflora, E. ochracea, E. penduliflora, and E. soteriana are endemic to Tabuleiro coastal forest, and E. handroi is the only record for Espírito Santo state. The most useful characters to distinguish the species are hair colours, especially in the floral structures, midvein on the adaxial surface of leaf blades, inflorescence type, connation and persistence of bracteoles, and the presence or absence of indumentum on the flowers’ hypanthia. Furthermore, morphological descriptions, distribution and phenology data, taxonomic comments, species illustrations, and an identification key for the species in the reserve are presented.