Myrcia Sect Research Articles

A taxonomic account of Myrciinae (Myrteae, Myrtaceae): generic and sectional placement of forgotten species and a list of all accepted species

The taxonomy of Neotropical Myrtaceae is known for the difficulties regarding specific and supraspecific taxonomic delimitations. In subtribe Myrciinae (tribe Myrteae) this situation is intensified due to the high diversity of species and relatively homogeneous morphology. Over the last two decades there has been a huge increase in Myrciinae systematic research. Following use of molecular phylogenetic works, several genera accepted in the 20th century were synonymised under a broader circumscription of Myrcia. Monophyletic sections that facilitated further taxonomic works were recognised. However, species with doubtful morphologies, scanty or missing data have remained untreated. This paper provides an update of the taxonomic status of these species as well as a list of accepted species of Myrciinae, assigned to sections of Myrcia. This work is based on a broad analysis of herbarium collections including types and the Myrciinae literature. Taxonomic comments are provided regarding species placement and features, and three new combinations, one new name, nine lectotypifications and two neotypifications are provided. Seven species are transferred to other genera or families. Thirty-seven species are listed as incompletely known due to absence of type specimens or any material that could clarify their taxonomic status. We currently accept 744 species of Myrcia (excluding the 37 species without known type collections and three species with uncertain generic placement), distributed between taxonomic sections as follows: Myrcia sect. Aguava (32 species), Myrcia sect. Aulomyrcia (162 species), Myrcia sect. Calyptranthes (248 species), Myrcia sect. Eugeniopsis (18 species), Myrcia sect. Gomidesia (67 species), Myrcia sect. Myrcia (158 species), Myrcia sect. Reticulosae (15 species), Myrcia sect. Sympodiomyrcia (28 species), Myrcia sect. Tomentosae (5 species), and clade 10 with nine species. Three species remain in Myrcia but are probably members of other taxa of Myrteae (M. cionei, M. skortzoviana) or other family (M. melastomoides), while two species of Myrcia (M. apiocarpa, M. sintenisiana) remain without a sectional placement. We highlight taxonomic issues to address in the future to improve systematic knowledge in Myrciinae.

Sinopse de Myrcia (Myrtaceae) no estado de Pernambuco, Brasil

Abstract: The present study is a synopsis of the species of Myrcia occurring in Pernambuco, Brazil. We recorded 30 species distributed in eight sections: M. sect. Aguava (4), Myrcia sect. Aulomyrcia (9), M. sect. Calyptranthes (3), M. sect. Gomidesia (5), M. sect. Myrcia (4), M. sect. Reticulosae (2), M. sect. Sympodiomyrcia (2) and M. sect. Tomentosae (1), beyond Myrcia sp. which has not been included in any section yet. Myrcia laricina (O. Berg) Burret ex Luetzelb. and M. hirtiflora DC. are new records for the State. Myrcia arenaria had the first record for humid forest in the municipality of Brejo da Madre de Deus. This study provides an identification key, comments on morphological distinction, geographic distribution and habitat for all taxa. In addition, distribution maps, photographic plates with the distinctive characteristics of the species are included and the updating names of Calyptranthes, Gomidesia and Marlierea under Myrcia.

Myrcia tenondeporan, a new species of Myrtaceae from the Atlantic Forest in the Serra do Mar Mountains, Brazil

Myrcia sect. Eugeniopsis is one of the nine sections of Myrcia (Myrciinae, Myrteae, Myrtaceae) and includes mostly species of the current synonym genus Eugeniopsis. Using fieldwork and the analysis of herbarium collections as a basis, we describe here a new species of this section, Myrcia tenondeporan, which is endemic to the Atlantic Forest in the Serra do Mar Mountains. The new species is related to Myrcia vellozoi and Myrcia multipunctata but differs mainly in the leaf shape and size, inflorescence structure and size of floral buds.

Leaf morphology and anatomy in Myrcia sect. Aulomyrcia (Myrtaceae): species circumscription and characterization of clades

Myrcia DC., a diverse neotropical genus of Myrtaceae, encompasses 793 species. However, species of Myrcia are similar and difficult to distinguish. In Myrcia sect. Aulomyrcia (O. Berg) Griseb., leaf features help distinguishing clades and species. Our aim is to provide leaf data for species of M. sect. Aulomyrcia’s clades F and G. We sampled 31 specimens of 13 species of Myrcia sect. Aulomyrcia ( Myrcia amazonica DC., Myrcia eumecephylla (O. Berg) Nied., Myrcia hexasticha Kiaersk., Myrcia insularis Gardner, Myrcia magna D. Legrand, Myrcia micropetala (Mart.) Nied., Myrcia neodimorpha E. Lucas & C.E. Wilson, Myrcia neoestrellensis E. Lucas & C.E. Wilson, Myrcia obversa (D. Legrand) E. Lucas & C.E. Wilson, Myrcia pyrifolia (Desv.) Nied., Myrcia riodocensis G.M. Barroso & Peixoto, Myrcia subobliqua (Benth.) Nied., and Myrcia tetraphylla Sobral) . Samples were subjected to sectioning and staining techniques for morphological and anatomical analysis through stereo and light microscopy. Leaf blade and petiole morphological and anatomical features were described carefully for the first time for these 13 species. We provided an identification key based on leaf features. Our findings are discussed in the light of Myrcia sect. Aulomyrcia systematics. We comment of the significance of petiolar and blade features, such as trichomes types and location, phyllotaxis, rhytidome peeling, periderm and lenticels, and petiole, blade, and vascular cylinder shape. Our study brings novel information on leaf structure variation in Myrcia sect. Aulomyrcia, delivering much needed data for species and clades circumscription and identification.

Two new remarkable species of Myrcia sect. Aguava (Myrtaceae, Myrteae) from the Brazilian Atlantic and Amazon forests

Two new remarkable species of Myrcia sect. Aguava (Myrtaceae, Myrteae) from the Brazilian Atlantic and Amazon forests

Myrcia urquiolae (Myrtaceae), a new species from eastern Cuba

In this work, Myrcia urquiolae, a new endemic species of the subspinous xeromorphic scrub on serpentinites of the Sierra de Nipe, is described and the geographical distribution of its only population is presented. Myrcia urquiolae belongs to the Myrcia sect. Myrcia, of whose other species in Cuba is distinguished by its linear leaves with a strongly twisted margin. Based on field exposures, M. urquiolae is categorized as Critically Endangered according to IUCN criteria.

A taxonomic account of Myrcia (Myrtaceae) at the sites of the Biological Dynamics of Forest Fragments Project, Amazonas, Brazil

Abstract Myrcia is the sole genus of the Myrciinae, one of the nine subtribes of Myrteae (Myrtaceae). The Amazon forest holds about one-quarter of the Brazilian species of Myrcia, but the genus is still understudied in this whole region. In this context, this study presents a floristic survey of Myrcia in the permanent plots of the Biological Dynamics of Forest Fragments Project (BDFFP), in Amazonas state, Brazil. The genus is represented by 36 species in the study area, comprehending 32% of its total richness in the Brazilian Amazon forest, with 19 of them endemic to this domain. Myrcia neospeciosa is reported as a new occurrence for Amazonas state and M. grandis is recorded for the first time from upland terra firme forests on clayish soils. Myrcia cuspidata, a species with calyptrate flowers, is classified under Myrcia sect. Aulomyrcia, representing the second taxon of the genus with this feature removed from Myrcia sect. Calyptranthes. Finally, morphological aspects of the infra-generic categories of Myrcia are reported more overlapping than previously thought. A map containing the location of the study area, an identification key, descriptions, comments, and figures are provided.

A taxonomic account of Myrcia (Myrtaceae) at the sites of the Biological Dynamics of Forest Fragments Project, Amazonas, Brazil

Abstract Myrcia is the sole genus of the Myrciinae, one of the nine subtribes of Myrteae (Myrtaceae). The Amazon forest holds about one-quarter of the Brazilian species of Myrcia, but the genus is still understudied in this whole region. In this context, this study presents a floristic survey of Myrcia in the permanent plots of the Biological Dynamics of Forest Fragments Project (BDFFP), in Amazonas state, Brazil. The genus is represented by 36 species in the study area, comprehending 32% of its total richness in the Brazilian Amazon forest, with 19 of them endemic to this domain. Myrcia neospeciosa is reported as a new occurrence for Amazonas state and M. grandis is recorded for the first time from upland terra firme forests on clayish soils. Myrcia cuspidata, a species with calyptrate flowers, is classified under Myrcia sect. Aulomyrcia, representing the second taxon of the genus with this feature removed from Myrcia sect. Calyptranthes. Finally, morphological aspects of the infra-generic categories of Myrcia are reported more overlapping than previously thought. A map containing the location of the study area, an identification key, descriptions, comments, and figures are provided.

Phylogeny and biogeography of Myrcia sect. Aguava (Myrtaceae, Myrteae) based on phylogenomic and Sanger data provide evidence for a Cerrado origin and geographically structured clades

Myrcia is one of the largest exclusively Neotropical angiosperm genera, including ca. 800 species divided into nine sections. Myrcia sect. Aguava is one of most complex sections of Myrcia due to high morphological variation and wide distribution range of some species, including M. guianensis, with distribution throughout South America and a complex taxonomic history. We used complete plastid DNA sequences data generated using next-generation sequencing of 45 terminals, mostly from Myrcia sect. Aguava. These data were combined with five target DNA regions (ITS, psbA-trnH, trnL-trnF, trnQ-rps16, ndhF) of additional terminals to increase taxonomic coverage. Phylogenetic analyses were conducted using a maximum likelihood approach, and divergence times and ancestral range distributions were estimated. Myrcia sect. Aguava is monophyletic and exclusively comprises species with trilocular ovaries but has no relationship with other groups within Myrcia that possess trilocular ovaries. Three main lineages that correspond to geographical distribution are recognized within Myrcia sect. Aguava. Multiple accessions reveal a non-monophyletic Myrcia guianensis and stress the biogeographical structure inside the group. Myrcia sect. Aguava had a probable mid-Miocene origin in the Cerrado, but lineages that persisted there diversified only more recently, when the present-day vegetation started to stabilize. Posterior migrations to Atlantic Forest, Amazon and Caribbean occurred at the end of Miocene, evidencing transitions from open and dry to forested and more humid areas that are less frequent in the Neotropics. Overall, it is observed that related lineages remained in ecologically similar environments. Future perspectives on Myrcia and Myrteae in the phylogenomic era are also discussed.

<p><strong><em>Myrcia</em></strong><em> </em><strong>sect. <em>Calyptranthes</em> (Myrtaceae) from the Atlantic Forest, Brazil</strong></p>

Myrcia sect. Calyptranthes is a section of the Neotropical genus Myrcia ranging from Mexico and the Caribbean to northern Argentina with ca. 260 known species. In Brazil ca. 78 species are known, of which ca. 53 are endemic, occurring mainly in the Atlantic and Amazon domains, with few species in the Caatinga and Cerrado. This paper is a taxonomic revision of 38 species from the Atlantic Forest including one newly described species Myrcia botryophylla. The treatment provides an identification key, taxonomic descriptions, phenology and geographic distribution information, nomenclatural updates, synonymy, and illustrations of the main morphological characters. The main character used for differentiating species is inflorescence pattern, but observation of several further characters including leaf size and shape, flower buds and indument assists in species determination. Of the 38 species recognized 29 are endemic to the Atlantic Forest domain and 9 occur in the Amazon, Cerrado and/or other habitats in South and Central America. Twenty-two new synonyms are proposed, two new combinations are made and 29 lectotypes are designated. One new species is described.

Two new species of Myrcia sect. Reticulosae (Myrtaceae) from the campo rupestre of Minas Gerais, Brazil

Two new species of Myrcia sect. Reticulosae, M. carassana and M. revoluta are here described and illustrated. Myrcia carassana was firstly recognized in 1908 by A. F. M. Glaziou but never validly published. This species is similar to M. venosissima but differs by reddish trichomes, inflorescences botryoid or reduced to simple dichasia with longer peduncles, obconic floral buds and calyx lobes internally densely pilose. Myrcia revoluta resembles M. reticulosa but differs by leaves strongly revolute, densely pilose abaxially when mature, and subterminal inflorescences subtended by reduced leaves.

Nomenclatural and taxonomic changes in tribe Myrteae (Myrtaceae) spurred by molecular phylogenies

Phylogenetic studies have highlighted incongruous generic placement and the usage of inappropriate names for species within tribe Myrteae (Myrtaceae). The genera affected are Calycolpus, Eugenia, Myrcia and Psidium. Eugenia aubletiana is legitimized by the designation of a lectotype and its usage proposed instead of Calycorectes bergii. Two generic transfers are proposed: Psidium sessiliflorum based on Calycolpus sessiliflorus and Myrcia neosericea, based on Eugenia neosericea. The re-instatement of Psidium cupreum, currently a synonym of Psidium rufum as an accepted species is proposed. Illustrations of the four affected species are furnished, as well as a map of occurrences of Psidium sessiliflorum. Tetramery associated to inflorescences reduced to 1(-3) flowers, an unusual combination of characters in Myrcia sect. Gomidesia, is identified in both Myrcia glaziovii and Myrcia neosericea, and a key to distinguish them is provided.

<p><strong><em>Myrcia adulterina</em></strong><strong> (Myrtaceae), a new species from the Atlantic Forest of Rio de Janeiro, Brazil</strong></p>

Myrcia adulterina, a new species from the Brazilian Atlantic Forest, is here described, illustrated and compared with morphologically related species. Additionally, its distribution map and a preliminary conservation status are presented. The new species is here inferred as belonging to Myrcia sect. Reticulosae due its leaves with raised venation, staminal ring densely pilose, hypanthium prolonged in a tube with glabrous inner walls and 3-locular ovaries. Within this section, the species is morphologically related to Myrcia pubipetala, from which it can be distinguished through the laxly reticulate leaf venation and thyrsoid inflorescences with all axes strongly flattened and striated when dry. Myrcia adulterina was misidentified during at least 15 years in herbaria under the name Marlierea tomentosa (currently synonym of Myrcia strigipes, a species belonging to Myrcia sect. Aulomyrcia), which is also morphologically similar. A brief discussion clarifying the morphological differences between these species is also presented.

<p><strong><em>Myrcia guedesiae</em></strong><em> </em><strong>(Myrtaceae), a new species from the Atlantic Forest of Bahia, Brazil</strong></p>

Myrcia guedesiae, a new species from the Atlantic Forest of South of Bahia State, is described and illustrated. Morphologically, the new species belongs to Myrcia sect. Aulomyrcia and is apparently related to M. hirtiflora and M. racemosa, differing in its leaves, inflorescences branches, number of flowers, hypanthium and calyx lobes on fruits.

<p><strong><em>Myrcia amplifolia</em></strong><strong> (Myrtaceae), a new species from the Atlantic Forest of southern Bahia, Brazil</strong></p>

Myrcia amplifolia, a new species from the coastal forest of southern Bahia, eastern Brazil, is here described and compared with morphologically similar species. Additionally, a morphological plate, distribution map and conservation assessment of the species are presented. We assign the new species to Myrcia sect. Calyptranthes with a reasonable reliability due to the combination: presence of cataphylls, inflorescences sympodially branching at the base and calyptrate flowers. Myrcia amplifolia seems to be closely related to M. carioca, from which it can be distinguished through the leaf blades strongly coriaceous (vs. chartaceous in M. carioca), leaf venation very slightly raised and barely conspicuous abaxially (vs. venation strongly raised and conspicuous abaxially), inflorescences with a shorter main axis (75–110 mm long vs. 130–270 mm long), and shorter first lateral branch (3.3–19 mm long vs. 48–95 mm long), and the calyptra acuminate (vs. rounded or shortly apiculate). It is also similar to M. boanova, differing by the leaf blades significantly larger (31–60 × 10–20 cm vs. 7–13 × 4.1–5 cm in M. boanova) and strongly coriaceous (vs. chartaceous), and the calyptra acuminate (vs. rounded) and smaller (2.3–2.6 × ca. 1.8 mm vs. 3.5–3.7 × 3.5–4 mm).

<p><strong><em>Myrcia suberosa</em></strong><strong>: a new species of <em>Myrcia </em>sect.<em> Eugeniopsis </em>(Myrciinae, Myrteae, Myrtaceae) endemic to the Atlantic Forest</strong></p>

A new species, Myrcia suberosa, is here proposed based in an ongoing taxonomic revision of Myrcia sect. Eugeniopsis, a group nearly endemic to the Atlantic Forest. Myrcia suberosa occurs in Brazil from Southern Bahia to Southern Rio de Janeiro states, but only three collections are known and the real distribution of the species is barely known. The new species is morphologically related to Myrcia pseudomarlierea and Myrcia teuscheriana, differing by sexual system, cork thickness, indument, and leaf and flower morphologies. Morphological description, images and conservation status are provided, as well as discussion about distribution, habitat, phenology and taxonomy.

<p><strong>Typifications, synonymizations and nomenclatural notes in <em>Myrcia</em> sect. <em>Reticulosae</em> (Myrtaceae)</strong></p>

Myrcia sect. Reticulosae comprises ca. 15 Brazilian endemic species distributed mainly in Atlantic Forest, Cerrado (Brazilian savanna) and Campo Rupestre (rocky outcrop vegetation). These species appeared as a cohesive group for the first time in recent phylogenetic hypotheses and their taxonomic revision is currently underway. In this context, this study aims to properly link the names to their respective type materials, presenting necessary lectotypifications and neotypifications, along with nomenclatural notes for nine species. Additionally, two new synonyms are proposed.

<p><strong><em>Myrcia lucasae </em></strong><strong>(Myrtaceae), a new species from the <em>campo rupestre</em> of Chapada Diamantina, Brazil</strong></p>

Myrcia lucasae (Myrcia sect. Gomidesia, Myrtaceae), a new species from the Bahia state, Brazil, is here described and illustrated. It differs from M. lughadhae, a closely related and sympatric species, by the strigose indumentum with ferruginous trichomes and the absence of ribs on fruits. It is also different and from M. virgata (Myrcia sect. Myrcia), by presenting thecae with irregular dorsal openings (characteristics of Myrcia sect. Gomidesia). Collections of M. lucasae have been constantly misidentified as the morphologically similar M. virgata, a species from a different section, which does not occur in the state of Bahia. Myrcia lucasae is endemic to the highly diverse campo rupestre vegetation of the Chapada Diamantina biogeographic province. We also provide preliminary conservation assessment, comments on distribution and ecological aspects of this new taxon.

<p><strong>New names in <em>Myrcia</em> sect. <em>Calyptranthes </em>(Myrtaceae)</strong></p>

After extensive molecular (Staggemeier et al. 2015; Santos et al. 2017; Wilson et al. 2016) and revisionary (e.g. Lima et al. 2018; Lourenço et al. 2018) work to maintain a manageable and monophyletic genus, Myrcia De Candolle (1827: 406) currently includes the previously recognized genera Calyptranthes Swartz (1788: 79), Gomidesia O.Berg (1855: 5) and Marlierea Cambessèdes (1832–1833: 373) (see Lucas et al. 2018). The majority of Calyptranthes species are now considered part of Myrcia sect. Calyptranthes (Sw.) A.R.Lourenço & E.Lucas (in Lucas et al. 2018: 3). As a result, Lourenço et al. (2018) recently transferred the continental species of Calyptranthes to Myrcia. Among these new names, two were subsequently found to be illegitimate and are herein corrected. The remaining species of Calyptranthes, mostly from the islands of the Caribbean, were transferred by Campbell et al. (2019).

New Synonyms and Typification of Myrcia sect. Myrcia (Myrtaceae)

Four new synonyms are here proposed for species of Myrcia sect. Myrcia: Myrcia brasiliae under M. lasiantha, M. pernambucensis under M. bergiana, M. recurvata under M. ovata, and M. sosias under M. undulata. Additionally, 42 lectotypifications for species of Myrcia sect. Myrcia are proposed herein.