Alessandro Oliveira de Souza

A New Species of Chamaecrista (Fabaceae, Caesalpinioideae, Cassieae) from the Highlands of Goiás, Brazil

Abstract A new species of Chamaecrista was found in the Chapada dos Veadeiros region, in the state of Goiás, Brazil, during an expedition to study the taxonomy of this genus. Chamaecrista floribunda is herein described, illustrated, and assigned to Chamaecrista sect. Absus subsect. Absus ser. Rigidulae. Comments about the ecology, distribution, and conservation status of the new species, as well as its morphological relationships, are provided. Additionally, a key to the species of Chamaecrista sect. Absus subsect. Absus ser. Rigidulae occurring in the Chapada dos Veadeiros region is presented.

Senna (Leguminosae, Caesalpinioideae) na Floresta Nacional de Silvânia, Goiás, Brasil

Senna is the second largest genus in the subfamily Caesalpinioideae with 300 species, of which 80 occur in Brazil. The taxonomy of the Brazilian species of Senna is poor studied, particularly in the Midwest of country. This study aimed to the taxonomic survey of the species of Senna occurring in the National Forest Silvânia, Goias. We found nine species which corresponds to 10% of the species occurring in Brazil and 37% present in the State of Goias. We provided identification key, descriptions, comments about geographical distribution, morphological similarities and, phenology, as well as images to eight species.

Chamaecrista elata (Leguminosae, Caesalpinioideae), a new species from the highlands of Goiás, Brazil

During the course of a taxonomic study of Chamaecrista sect. Absus subsect. Absus ser. Rigidulae, a new species of Chamaecrista was discovered growing in disturbed areas of Cerrado sensu stricto in the municipality of Alto Paraíso de Goiás. Chamaecrista elata is herein described and illustrated. Morphological comparison with related species and information on geographical distribution, environmental preferences, conservation status, and phenology are provided.ResumoDurante o estudo taxonômico de Chamaecrista sect. Absus subsect. Absus ser. Rigidulae, uma nova espécie de Chamaecrista foi descoberta crescendo em áreas perturbadas do Cerrado sensu stricto no munícipio de Alto Paraíso de Goiás. Chamaerista elata é aqui descrita e ilustrada. Além disto, são fornecidas informações como comparação morfológica com espécies relacionadas, distribuição geográfica, preferências ambientais e status de conservação.

A New Species Hidden in the Lowlands of Tocantins, Brazil: Chamaecrista tocantinensis (Fabaceae)

Abstract Chamaecrista tocantinensis, a new species of Chamaecrista sect. Absus subsect. Absus ser. Paniculatae endemic to the Jalapão region in the state of Tocantins, Northern Brazil, is herein described and illustrated. The systematic position, conservation status, flowering and fruiting period, geographical distribution, and morphological relationships of this novel species with C. claussenii var. megacycla, C. lundii, and C. orbiculata var. orbiculata are discussed. A key to all taxa of Chamaecrista hitherto known from the state of Tocantins, including ten new state records, is also provided.

Taxonomia e diversidade do gênero Senna Mill. ( Leguminosae, Caesalpinioideae, Cassieae ) no estado de Goiás, Brasil

E apresentado o tratamento taxonomico para as especies do genero Senna ocorrentes no estado de Goias. Foram encontradas 25 especies, quatro subespecies e 22 variedades. Senna pilifera var. tubata H.S. Irwin & Barneby, S. silvestris var. guaranitica (Chodat & Hassl.) H.S. Irwin & Barneby, S. splendida var. splendida (Vogel) H.S. Irwin & Barneby e S. splendida var. gloriosa H.S. Irwin & Barneby sao primeiramente referenciadas para Goias, enquanto que S. latifolia (G. Mey.) H.S. Irwin & Barneby e S. spinescens (Hoff manns. ex Vogel) H.S. Irwin & Barneby, embora citadas para Goias, foram excluidas deste estudo, porque suas areas de ocorrencia condizem com os limites atuais do estado de Tocantins. Sao apresentados chave de identifIcacao, descricoes, ilustracoes, e comentarios sobre relacoes morfologicas, ecologia e distribuicao geografica dos taxons.

Chamaecrista belladonna (Fabaceae, Caesalpinioideae, Cassieae), a new threatened endemic species from Goiás, Brazil

Chamaecrista belladonna is described and illustrated. It is assigned to Chamaecrista sect. Absus subsect. Absus series Microphyllae. The species grows on mixed sand-clay soils near rock outcrops in the Chapada dos Veadeiros region in the Brazilian state of Goiás. Since it is found in an area 0.4 km2, surrounded by agricultural land and under intense anthropogenic pressure, it is here considered Critically Endangered. The novel species can be distinguished from all other species of the series by having pseudo-terminal inflorescences (borne in the axil of the distal-most leaf at the ends of branches and appearing opposite the leaf) with flexuous axis and leaflets with mixed acrodromous-brochidodromous venation. Discussion is provided about the distribution, phenology, and conservation status of the new species, as well as its morphological relationships with the similar species C. dumalis and C. imbricans. Images and descriptions of the leaf anatomy of the new species are also given.