To measure the biodiversity of flora in the lower basin of the Reque river, 8 perpendicular transects were traced at distances of 10 x 250 m on each side of the Reque river bed from 20 to 30 October 2020. In them, flora species were identified; The number of specimens per species and transect were recorded in a Microsoft 2013 Excel spreadsheet, saved with the csv extension delimited by commas. The Species Diversity and Richtnes and PAST software were used to determine Alpha and Beta Biodiversity Indices. It was concluded that the most abundant plant families were Fabaceae with species of Prosopis sp (algarrobo); Acacia huarango (huarango), Crotolaria incana; Cajanus cajan (stick beans) and Inga Fewelei (guava) and Saccharum officinarum (sugarcane Distichlis spicata (salty grass), Zea mays (corn) and Sorghun halepensis (sorghum) of the Poaceae family. The Shannon-Wiener index varied from ...