Mimosoideae (Leguminosae) in the Brazilian Chaco of Porto Murtinho, Mato Grosso do Sul

Abstract

This research consists of the taxonomic-floristic treatment of taxa of Mimosoideae occurring in the Brazilian Chaco. The specimens analyzed were collected from 2004 to 2012 in Chaco remnants located in southwestern Mato Grosso do Sul, Brazil. Mimosoideae is represented by 39 taxa belonging to 14 genera; among the most representative, Mimosa (16 taxa) and Prosopis (4 taxa) are highlighted. Chloroleucon chacoense, Mimosa centurionis and Prosopis alba are new records for the Brazilian Flora. Prosopis nigra has its occurrence expanded. Mimosoideae is the second subfamily in species richness compared with other subfamilies of Leguminosae studied in the Brazilian Chaco. This work includes morphological descriptions, identification keys, illustrations and taxonomic comments.

Leguminosae endemic to the Chaco facing quaternary climate fluctuations

“…The fragmentation of suitable habitats in the LIG is expected, given that a warmer and wetter climate is more suitable for forest expansion (Otto-Bliesner et al 2006). This is due to the fact that the species analysed occur in the wet areas of the Chaco in Paraguay and Brazil (Wunderlin 1968; Burkart & Simpson 1977; Souza-Lima et al 2017). Consequently, Bauhinia hagenbeckii and Prosopsi rubriflora, following this expansion, fragmented mainly in the north-western and southern regions of South America and along the coast of Brazil, considered regions of higher wetness during the LIG (Carnaval & Moritz 2008;Carnaval et al 2009;Cheng et al 2013;Carnaval et al 2014).…”

“…In Brazil there are records only for the Mato Grosso do Sul state (Silva & Tozzi 2015). Neltuma rubriflora is an important indicator of Chaco wet areas and occurs in Paraguay (Burkart & Simpson 1977) and Brazil (Souza-Lima et al 2017).…”

“…A number of floristic studies have shown the Leguminosae richness in the Chaco (Adámoli et al 1972;Ortega-Torres et al 1989;Lewis 1991;Spichiger et al 1991;Navarro et al 2006;Noguchi et al 2009;Torrela et al 2011;Gimenez et al 2011;Giorgis et al 2011;Freitas et al 2013;Neves et al 2015;Souza-Lima et al 2017;Sartori et al 2018;Morales et al 2019;Sinani et al 2019). In addition, species such as Bauhinia hagenbeckii, Muellera nudiflora and Neltuma rubriflora, of restricted distribution, suggest areas of endemism in the Chaco wet sector (Wunderlin 1968;Burkart 1969;1976;Vaz et al 2010).…”