Leidiana Lima dos Santos

Myrcia spiciformis , a new species from the eastern Amazon, is described and illustrated. It is characterized by twigs with dense rufous pubescence, a spiciform panicle, pedicels absent or up to 3 mm long, and flowers with 4–5 sepals. The staminal ring is glabrous and the hypanthium is pubescent. Morphologically, M . spiciformis is related to M . coumete . The new species is endemic to the Amazon Biome, with records from Maranhão and Pará states, where it grows in both non-flooded upland ( terra-firme ) and seasonally flooded ( várzea ) forests. It is provisionally assessed as Endangered (EN) according to the IUCN Red List criteria, due to restricted distribution of the species and vegetation loss resulting from anthropogenic pressure in the occurrence area.

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.

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.

Angiosperm species growing in a fragment of Lowland Semideciduous Seasonal Forest in the Tapacurá Ecological Station (TES) in Pernambuco State (Brazil) were surveyed. Botanical collections to compose a species list were undertaken and these species identified by comparisons with specimens deposited in the HST, PEUFR and IPA herbaria, in addition to online database queries. A total of 479 species were identified, belonging to 81 families and 285 genera. The families with the largest numbers of species were Fabaceae (68), Rubiaceae (25), Malvaceae (20), Myrtaceae (20), Cyperaceae (19), Poaceae (19), Bromeliaceae (18), Euphorbiaceae (17), Asteraceae (16), and Sapindaceae (14), which together accounted for 49.27% of the total number of species. Great similarity was observed between our results and surveys of other lowland forests in northeastern Brazil, with the families Fabaceae, Rubiaceae, and Myrtaceae having the greatest species richness. This study added 44 new occurrences for Pernambuco State, demonstrating the richness and abundance of TES taxa and the importance of their conservation to the regional flora.

Premise of research. Myrcia s.l. is the largest exclusively Neotropical genus of Myrtaceae, comprising about 800 species. This large genus is divided into 10 clades, most of these recently publishe...

Three new species of Myrcia are described, illustrated and discussed. Myrcia rionegrensis from the Brazilian Amazon is related to M. clusiifolia from which it differs in having leaves with acute apex and ribbed fruits (vs. rounded apex and smooth fruits in M. clusiifolia); Myrcia microcalyx is similar to Myrcia scytophylla but differs in having pubescent staminal ring and ellipsoid fruits (vs. glabrous staminal ring and globose fruits in M. scytophylla) and Myrcia peruviana is related to M. riverae, but differs in having smaller leaves and flower buds and ellipsoid fruits (vs. globose in M. riverae).

A vegetação arbóreo-arbustiva é a fitofisionomia que mais se destaca no ambiente de caatinga. A composição florística e fitossociologia desse bioma contribuem para a dinâmica da vegetação e o entendimento de sua estrutura colabora com ações voltadas à melhor preservação e conservação desse ecossistema brasileiro. Diante do exposto, o estudo objetivou identificar a composição florística e a estrutura do componente lenhoso de duas áreas com vegetação arbóreo-arbustiva localizadas em uma área sedimentar do Parque Nacional do Catimbau (Neossolos Quartzarênicos). Foram instalados 100 pontos amostrais por área, distribuídos em 10 transectos, 30 m paralelos e equidistantes. Em cada ponto foram amostrados quatro indivíduos com circunferência ? 9 cm ao nível do solo. Na área 1 foram encontradas 16 famílias, 24 gêneros e 26 espécies, com maior número de indivíduos para Fabaceae (100), Malpighiaceae (87), Myrtaceae (60) e Bignoniaceae (42). Na área 2 foram registradas nove famílias, 20 gêneros e 27 espécies, com maior número de indivíduos para Fabaceae (209), Euphorbiaceae (70), Verbenaceae (46) e Cactaceae (17); o VI mais alto foi registrado para Chamaecrista brachystachya Conc., L. P. Queiroz & G. P. Lewis e Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson em suas respectivas áreas. As duas áreas apresentaram composição florística distinta, espécies comuns às comunidades da caatinga, elementos característicos de outros tipos de vegetação e uma espécie rara do Brasil (Jacaranda rugosa A.H. Gentry).