A new species of Trichilia (Meliaceae) from the Atlantic Forest of Brazil

Abstract A new species of Trichilia (Meliaceae) from Southeastern Brazil is here described, illustrated and compared to its closest related species. Trichilia arenaria sp. nov. is morphologically similar to T. casaretti, T. elegans and T. pallens. An identification key and comparison table for T. arenaria and those three species from Atlantic Forest of Espírito Santo are also presented.


Introduction
Trichilia Browne belongs to the Meliaceae, which comprises nearly 550 species distributed in about 50 genera. The family has a cosmopolitan distribution (although mostly pantropical) and occurs in various types of habitats, ranging from humid forests to semiarid environments (Pennington & Styles 1975;Pennington et al. 1981;Mabberley et al. 1995). The Neotropics, African continent and Malaysia region are remarkably important for the diversity in this group (Pennington et al. 1981;Mabberley et al. 1995). Trichilia is a tropical genus of about 103 species, mostly found in humid forests, of these 81 are distributed in the Neotropics with the remaining 22 species from Africa (Wilde 1968;Pennington 2016). Trichilia species are distributed in almost all states in Brazil, possessing 46 species (24 are endemic) occurring especially in the Amazon and Atlantic Forest domains (BFG 2018).
Trichilia was described by Browne (1756) and after his publication, Candolle (1878aCandolle ( ,b, 1905Candolle ( , 1907 was responsible for publishing a great number of new species. Aside of these studies, the efforts of Wilde (1968), who presented a synopsis of the genus, were important to the systematic of the African species. We also highlight the works of Pennington et al. (1981) and Pennington (2016), which contributed significantly to the taxonomy of Trichilia by presenting a treatment of the American species.
Trichilia is recognized by flowers usually unisexual (plants dioecious), less frequently bisexual and then plants polygamous, stamens with filaments completely or partially united, rarely free, with the anthers inserted at the apex of staminal tube or over the free filaments, ovary with 1-2 collateral or superimposed ovules per locule, and loculicidal capsules with unwinged seeds (Wilde 1968;Pennington et al. 1981;Pennington 2016).
The new species of Trichilia proposed here was found in regions with sandy soils in the coastal plain of Espírito Santo state, located in Southeastern Brazil, during a taxonomic study of Meliaceae (Flores et al. 2017).

Material and Methods
This study is based on the analyses of morphological features of botanical specimens deposited in CVRD, ESA, MBM, SPF, RB, UEC e VIES herbaria (acronyms according to Thiers, continuously updated). Extent of Occurrence (EOO) and Area of Occupancy (AOO) were estimated using the Geospatial Conservation Assessment Tool (GeoCAT, see Bachman et al. 2011) in order to evaluate the conservation status of the new species following the IUCN criteria (IUCN 2012). Finally, we obtained the approximate geographic coordinates from the information presented in the specimen labels of the herbaria and then produced a distribution map using QGIS (QGIS 2018). Trichilia arenaria is positioned in a group of species in which the flowers have imbricate petals and filaments completely united. Trichilia arenaria is similar to T. pallens because both species have homomorphic leaflets, domatia only on the axils of secondary veins, and papillose fruits. Trichilia arenaria, however, differs from T. pallens by the unifoliolate or trifoliolate leaves with conspicuous translucent glandular punctations and striations vs. (3-)5-7(-9) leaflets, absent or inconspicuous translucent glandular punctations and striations, ovary densely pubescent (vs. ovary glabrous), and capsule trigonal (vs. broadly ovoid to globose).
The specific epithet refers to its occurrence in sandy substrates.
Flowering between October and January, and fruiting between December and January, with one collection fruiting in May.
Trichilia arenaria occurs in areas with sandy soils in the coastal plain of the state of Espírito Santo, Brazil. The species was found in the "Tabuleiro" Forest from the municipality of Linhares and in the "Restinga" of Guarapari (Fig. 2).
Trichilia arenaria is known by few collections in Linhares and Guarapari municipalities inside protected areas (Reserva Natural Vale e Parque Estadual Paulo César Vinha). Following the IUCN (2012) criteria the species is evaluated as Endangered, ENB1ab(i,iii), based on extent of occurrence (EOO = 593,590 km 2 ), Area of Occupancy (AOO = 36,000 km 2 ) and the declining population and habitat quality due to the expansion of urban and agriculture areas, extraction of sand and cultivation of Eucalyptus species.
Trichilia arenaria morphologically resembles T. casaretti C. DC., T. elegans A. Juss., and Trichilia pallens C. DC., which also have imbricate petals, stamens with filaments completely united and are present in Southeastern Brazil. Trichilia arenaria is recognized by the unifoliolate or trifoliolate leaves with conspicuous translucent glandular punctations and striations, domatia only on the axils of secondary veins, ovary densely pubescent,