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Chromosome numbers were counted for 23 species of Crotalaria native to Brazil. Among these data there were new counts for 15 taxa, and some confirmed previous reports or represented numbers that were different from those cited previously. The chromosome numbers most frequently found were 2 n = 16 and 2 n = 32. Only C. incana L. had 2 n = 14 and C. tweediana Benth. had 2 n = 54. The counts 2 n = 32 and 54 were found in species of section Calycinae and 2 n = 16 and 14 in species of section Chrysocalycinae . The data revealed the importance of chromosomal parameters in the characterization of sections Calycinae and Chrysocalycinae in Brazil. We discuss the systematic significance and evolutionary aspects for the genus, comparing the results with the two sections that are native in Brazil.

Summary. The genus Orthophytum Beer comprises 53 species, all narrow endemics to south-eastern and northeastern Brazil. In this study we present meiotic and mitotic chromosome numbers of 12 species of this important genus in Bromeliaceae. For six of these taxa we are reporting the first cytogenetic study. Orthophytum albopictum, O. amoenum and O. burle-marxii presented 2n = 100 chromosomes and O. hatschbachii, O. mucugense, O. vagans, O. supthutii, O. zanonii and O. ophiuroides showed 2n = 50 chromosomes. These results are consistent with the proposed basic number of x = 25 for Bromeliaceae family. In the genus Orthophytum, polyploidy seems to play an important role in chromosome evolution associated with habitat differentiation among diploid and polyploid species.

-The chromosomes of 14 species belonging to two subfamilies of the family Rubiaceae collected in the Brazilian cerrado were studied. In the subfamily Ixoroideae, five species (Alibertia concolor, A. edulis, A. sessilis, Genipa americana and Tocoyena formosa) had a chromosome number of 2n = 22 and one (Amaioua intermedia) showed polyploidy, with 2n = 66. All of the chromosome numbers were multiples of the more common basic number for this family (x = 11). In the subfamily Rubioideae, variations in the number of chromosomes were observed among tribes and genera, with 2n = 20 in the tribe Coccocypseleae (Coccocypselum lanceolatum), 2n = 28 in Spermacoceae (Borreria latifolia, B. verticillata and Richardia brasiliensis) and n = 11 in Coussareeae (Coussarea hydrangeifolia). In the tribe Psychotrieae, the variations included n = 11 (Palicourea rigida), 2n = 22 (Psychotria hoffmannseggiana) and 2n = 32 (Psychotria deflexa). The ideograms elaborated for 12 species were symmetrical (TF% varied from 47.45 to 38.01). The size of the chromosomes ranged from 1.26 to 7.33 µm and most were metacentric. The results show that chromosome size and morphology were insufficient to differentiate among groups within the Rubiaceae.

Números cromossômicos em Kleberiella V.P. Castro & Cath. (Orchidaceae, Oncidiinae) e gêneros afi ns RESUMO (Números cromossômicos em Kleberiella V.P. Castro & Cath. (Orchidaceae, Oncidiinae) e gêneros afi ns). Este trabalho teve como objetivo principal realizar a análise citotaxonômica de espécies fi logeneticamente relacionadas dentro dos gêneros Kleberiella, Alatiglossum e Neoruschia com base na determinação dos seus números cromossômicos a partir dos seus meristemas radiculares. Foram obtidos os números cromossômicos de todas as espécies de Kleberiella (seis espécies), Neoruschia (monoespecífi co) e de quatro das nove espécies conhecidas para Alatiglossum stricto sensu. Exceto para K. longipes, A. barbatum e A. micropogon, os quais corroboram com resultados anteriores, todos os outros números cromossômicos são inéditos. A contagem cromossômica se mostrou como um caráter taxonômico útil na delimitação de Alatiglossum fuscopetalum (2n = 52) e do gênero Neoruschia (2n = 48) das outras espécies analisadas. Entretanto não se mostrou efi ciente para delimitação entre as espécies de Kleberiella (todas com 2n = 56) e para separar este gênero de Alatiglossum no qual a maioria das espécies analisadas apresentou 2n = 56. O numero básico sugerido para Alatiglossum e Kleberiella é x = 28 e para Neoruschia x = 24. Th is work aimed to provide cytotaxonomical analysis of species phylogenetically related within the genera Kleberiella, Alatiglossum and Neoruschia based on the determination of chromosome numbers from root meristems. We obtained the chromosome numbers of all species of Kleberiella (six species), Neoruschia (monospecifi c) and four of the nine known species of Alatiglossum stricto sensu. Except for K. longipes, A. barbatum and A. micropogon, which corroborate previous results, all other chromosome numbers are unpublished. Chromosome counting proved useful as a taxonomic character in the delimitation of Alatiglossum fuscopetalum (2n = 52) and the genus Neoruschia (2n = 48) from the other species analyzed. However it was not effi cient for delimitation between Kleberiella species (all with 2n = 56) and to separate this genus from Alatiglossum in which most of the species studied had 2n = 56. Th e provable basic number for Alatiglossum and Kleberiella is x = 28 and for Neoruschia x = 24. Palavras-chave: