GENERAL INFORMATION 1. Title of Dataset: Sampling of riparian vegetation along a mountain river in Oaxaca, Mexico. 2. Author Information Name: Nihaib Flores-Galicia Institution: Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México Email: nihaibfloresg@gmail.com 3. Date of data collection: 2017-05 to 2017-11 4. Geographic location of data collection: Mountain river in the Papaloapan basin, Oaxaca, Mexico. 5. Information about funding sources that supported the collection of the data: Support Program for Research Projects and Technological Innovation (PAPIIT IN301118) SHARING/ACCESS INFORMATION 1. Links to publications that cite or use the data: Flores-Galicia, N et al. 2021. Environment driven changes in riparian plant communities along a mountain river. Ecology and Evolution. DATA & FILE OVERVIEW 1. File List: Upper stratum data (csv): The data of all the individuals registered in the upper stratum are found. Middle stratum data (csv): The data of all the individuals registered in the middle stratum are found. Low stratum data (csv): The data of all the individuals registered in the low stratum are found. Site localization (csv): The location in decimal degrees coordinates of the sampling sites and distance to the origin of the river. METHODOLOGICAL INFORMATION 1. Description of methods used for collection/generation of data: In the river, 15 sampling sites were established in the first 16 km of the stream (following the path of the river). To floristically characterize the riparian communities that develop along the river, at each sampling site all vascular plant species were recorded in plots of different sizes depending on the stratum studied, in each parcel all individuals per species (except for low stratum) and his normalized diameter (ND= diameter at height of 1.3 m) was registered. Due to the rugged topography of the area, the plots were placed on a river bank. The strata were separated because different life forms dominated the upper and middle layer (dominated by trees and shrubs) and the lower layer (dominated by herbaceous plants). For the upper stratum, all individuals with more than 1 cm of ND were measured in two plots of ~100 m2 (3x33.3 m). For the middle stratum, all the individuals smaller than 1 cm of ND were measured in two plots of 50 m2 (2x25 m). Finally, for the lower stratum, the coverage of all individuals less than 1 m tall were recorded in two plots of 1 m2 (1x1 m).