Macrophytes of the Capitão Poço river micro-basin, State of Pará, Eastern Amazon, Brazil: floristic composition and identification key for the species

ABSTRACT We aimed to characterize the floristic composition, detect the life forms, and provide an identification key for the macrophyte species of the Capitão Poço river micro-basin in the State of Pará, located in the Eastern Amazon. The collected specimens were identified and deposited in the HCP herbarium. We found 23 species distributed in 19 genera and 14 families of macrophytes. The families with the highest species richness were Cyperaceae (six spp.), Poaceae (three spp.), Onagraceae and Plantaginaceae (two spp. each). We present here the first record of Dichanthelium aequivaginatum from the Brazilian Amazon and the Northern region of Brazil. We suggest that floristic-taxonomic studies of macrophytes in the hydrographic basins of the northeastern region of Pará should be intensified in order to better understand the regional flora of this group.