Circumscription and synopsis of Eugenia section Speciosae Bünger & Mazine (Myrtaceae)

Abstract A new section of Eugenia (Myrtaceae) is described, segregate from Eugenia sect. Phyllocalyx. Phylogenetic studies suggest that Eugenia sect. Phyllocalyx as traditionally delimited is paraphyletic. To maintain the monophyly of each of the sections in Eugenia s.l., we herein opt to circumscribe a new section and recognize six taxa in sect. Speciosae, which has a distribution mostly in southeastern Brazil and northern South America. Nomenclatural notes are made and a taxonomic key is provided for the species of the section.


Introduction
Eugenia Linnaeus is a widespread tropical genus with about 385 species in Brazil (Govaerts et al. 2014, most of which grow along the Brazilian Atlantic rainforest biome (Oliveira-Filho and Fontes 2000). Eugenia is unique among Myrtaceae in having a native distribution that spans nearly the entire geographic range of the family (Snow 2011).
Th e genus Phyllocalyx was segregated from Eugenia by Otto Berg (1856) being characterized especially by peduncles with leaf-like bracts and showy sepals, proportionally larger than the fl owers. Th e name Phyllocalyx O. Berg (1856) is also illegitimate, being a later homonym of Phyllocalyx A. Rich. (1847). When Niedenzu, in 1893, transfered Phyllocalyx O. Berg to Eugenia, he named it Eugenia sect. Phyllocalyx. Th is name is treated as nomen novum and has the same type as the illegitimate name. It has priority from 1893 and must be cited as Eugenia sect. Phyllocalyx Nied., not as Recently, based on a molecular (nuclear and plastid markers) phylogenetic analysis, Mazine et al. (2014) recognized nine clades in Eugenia s. l. Th ey also confi rmed the inclusion of Calycorectes, Hexachlamys, and Phyllocalyx in Eugenia. Th e "Phyllocalyx clade" or "clade 6" sensu Mazine et al. (2014) refers to Eugenia sect. Phyllocalyx Nied. comprising c. 15 species widely distributed in the Atlantic Forest, from eastern Brazil to Paraguay. Th e section is characterized by peduncles with leaf-like bracts and showy sepals, proportionally larger than the fl owers (Berg 1856, under Phyllocalyx), and is currently being monographed (Bünger et al. unpubl. res.). A remarkable result of Mazine et al. (2014) is the placement of Eugenia wentii -traditionally included in Eugenia sect. Phyllocalyx (Mc Vaugh 1969) -in "clade 9" althoug this clade does not have any support.
After broad sampling of Eugenia sect. Phyllocalyx within a molecular framework (using fi ve markers, one nuclear and four plastid) (Bünger et al. unpubl. res.), results show that Eugenia sect. Phyllocalyx sensu Berg emerges as a paraphyletic group. Th e clade containing most species previously placed in section Phyllocalyx and also containing the type-species of the section (Eugenia involucrata DC.) emerges as a wellsupported monophyletic group (PP Bayes: 0.99; PP Beast: 0.97; ML: 75). A second, also well-supported clade (PP Bayes: 1; PP Beast: 1; ML: 100) includes species previously included in Eugenia sect. Phyllocalyx (Eugenia bunchosiifolia Nied., E. hermesiana Mattos, E. longipetiolata Mattos, E. macedoi Mattos, E. speciosa Cambess and E. wentii Amshoff ) but emerges with high support (PP Bayes: 0.99; PP Beast: 0.99; ML: 72) as sister to clade 9 sensu Mazine et al. (2014). Now, the clade 9 also emerges with high support (PP Bayes: 0.99; PP Beast: 0.99; ML: 86). Bünger et al. (unpubl. res.) also have optimised morphological characters across the molecular tree, presenting useful results with which to distinguish the sections. Results indicated that these characters are uncommon in Eugenia s.l. and can therefore be used to support placement of species inside a genus/subgenus/section (e.g. Berg 1857, Niedenzu 1893, McVaugh 1969, Mattos 1989. Although these two clades do not emerge in a monophyletic group, they share the fl oral characters of showy sepals and bracteoles that could be homoplastic characters in Eugenia s.l.
To avoid continued recognition of a paraphyletic taxon we herein recognize a new section called Eugenia sect. Speciosae and provide the new circumscription of Eugenia sect. Speciosae, an identifi cation key and a synopsis of the known species of this new section.

Taxonomic synopsis
Th e section name "Speciosae" was chosen based on the fact that Eugenia speciosa is the most geographically widespread species in this group. Th e specifi c epithet "speciosa" is also the oldest within the section (Cambessédes 1832) Eugenia sect. Speciosae Bünger & Mazine, sect. nov. urn:lsid:ipni.org:names:77153396-1 Notes. Trees or shrubs; hairs simple. Indeterminate infl orescence which produces a fl oral region that, for instance, produces monads, dyads or triads and vegetative innovative shoots, as an auxotelic infl orescence (Briggs and Johnson 1989); bracteoles linear or narrowly elliptic persistent at anthesis but caducous in mature fruits; fl owers showy always 4-merous; sepals showy, free, foliaceous, sepals and petals concealing the apex of the bud; ovary 2-locular; ovules 2-many, placenta axile. Fruit crowned by the calyx lobes. Seeds 1-2; seed coat membranous or cartilaginous; embryo with fused cotyledons.
Type Notes. Eugenia macedoi is known only by two specimens colected in Minas Gerais and Goiás States (Brazil). Th is species is a shrub growing in the Cerrado biome (like savannas). Apparently it is the only species of the section that occurs in dry areas. Th is species has glabrescent leaves without cartilaginous margins, dots visible on both faces, leaf apices are acute, and the hypanthium is velutinous.   Notes. Eugenia speciosa is a tree 5-12 m high from Atlantic Forest in southern and southeastern Brazil. It is common in rainforests and "restingas". Th is species also occurs in montane Atlantic Forest in Minas Gerais State (Brazil) and also occurs in Paraguay, Argentina, Uruguay and Bolivia. Th is species has leaves with visible, salient dots on both faces, glabrous, obtuse apices with cartilaginous margins and a glabrous hypanthium.

Eugenia speciosa
Th e lectotypes chosen for Phyllocalyx limbatus and Phyllocalyx macrosepalus are from BR; they were seen and we consider that the specimens that well represent the names. Th e lectotype that was chosen for Phyllocalyx limbatus is a specimen that is a duplicate (isotype) of the specimen that was in B which was destroyed in the Second World War. For thus, we consider it as the lectotype for this species.