Family Fabaceae of Morro Santana, Porto Alegre, RS, Brazil: taxonomic and ecological aspects

Abstract

The granitic hills of Porto Alegre cover ca. 24 % of city area and shelter meaningful original vegetation remnants, which one is Morro Santana that shows to be a priority area to conservation. This work aimed to survey Family Fabaceae of this hill, drawing up a list of Fabaceae species, in addition keys for identification of taxon corroborated, technical features and habit, flowering, fructification information. Furthermore a floristic comparison with other granitic hills of Porto Alegre. Thirty five field expeditions on study area were performed for floristic list, bibliographic review of species features and a similarity floristic analysis. Sixty two species were confirmed, distributed on subfamilies Faboideae (46 spp.), Mimosoideae (11 spp.) and Caesalpinioideae (5 spp.), among which herbaceous habit was prevailing. The tribes better represented were Phaseoleae and Dalbergieae (Faboideae) which together perform 50% of total species identified. The four genera with the largest representation were: Desmodium Desv. e Zornia J.F. Gmel. (both with 5 spp. each one ), further on Galactia P. Browne and Mimosa L. (with 4 spp.). The floristic similarity analysis showed that legumes species composition between Morro Santana and the other hills as Polícia , Osso and Parque Estadual de Itapuã is distinct, nevertheless so similar to Morro São Pedro. Considering the floristic richness Morro Santana has the largest number of species compared to Parque Estadual de Itapuã (59 spp.), Morro São Pedro (47 spp.), Morro da Polícia (36 spp.) and Morro do Osso (25 spp.).