Primeros estudios cariotípicos en Mimosa farinosa y M. velloziana (Leguminosae, Mimosoideae)

The first karyotype studies in Mimosa farinosaand M. vellozianaare presented. The chromosome number of M. farinosa, 2n = 2x = 26 (Mimosasection Batocaulonseries Farinosae) is mentioned for the first time, while the chromosome number of M. vellozianavar. velloziana, 2n = 4x = 52 (Mimosasection Mimosaseries Mimosasubseries Mimosa) is confirmed. The formula and parameters of karyotype (chromosome length and A1 and A2 asymmetry indexes) were analyzed. The karyotype formula of M. farinosa(16m+10sm) and M. vellozianavar. velloziana (48m+4sm) were calculated. Mimosa farinosahas a more asymmetric karyotype and larger chromosome size than M. vellozianavar. velloziana. A1 index, total chromosome length, and chromosome length per haploid genome showed significant differences between the two taxa. These results agree with differences previously found among other members of series Farinosae and subseries Mimosa, suggesting that certain karyotype parameters could have cytotaxonomic interest in some groups of species of this genusSe presentan los primeros estudios de cariotipo en Mimosa farinosa y M. velloziana. Se cita por primera vez el número cromosómico de M. farinosa, 2n = 2x = 26 (Mimosa sección Batocaulon serie Farinosae) y se confirma el número cromosómico de M. velloziana var. velloziana: 2n = 4x = 52 (Mimosa sección Mimosa serie Mimosa subserie Mimosa). Se analizó la fórmula y los parámetros del cariotipo (longitud cromosómica e índices de asimetría A1y A2). Se determinaron las fórmulas cariotípicas de M. farinosa (16m+10sm) y de M. velloziana var. velloziana (48m+4sm). M. farinosa posee un cariotipo más asimétrico y mayor tamaño cromosómico que M. velloziana var. velloziana. El índice A1, el largo cromosómico total y el largo cromosómico por genoma haploide exhibieron diferencias significativas entre ambos taxones. Estos resultados concuerdan con diferencias halladas previamente entre otros representantes de la serie Farinosae y la serie Mimosa subserie Mimosa, lo que sugiere que algunos parámetros evaluados tienen interés citotaxonómico en grupos de especies de este género

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora