Birdsfoot trefoil, which is native to Turkish flora, is the most valuable and common Lotus species in Turkey. However, existing information on the ecology, distribution, and plant traits of the Birdsfoot trefoil is scant for the natural flora of Turkey. Therefore, seeds from 126 wild birdsfoot trefoil (WBT) populations were collected from plants spontaneously occurring in natural pasture and rangelands located (altitudes ranged from 5 to 2193 m a.s.l.) in the Black Sea Region of Turkey. These populations were grown under the same ecological conditions in 2010 and 2011 to determine the ecotype traits of the WBT and the relationships between these traits and the geographical features of the locations. The WBT was present (1-25% of botanical composition) in all ranges of altitude, although there was an increase in the presence and frequency of WBT with increasing altitude until 1000 m a.s.l. There were negative correlations between some traits (dry matter and seed yields, morphologic, and also root and crown-rot resistant traits) and altitude at which the seeds were collected. The data revealed that there was evidence of considerable inherent variations in all traits and thus there was a huge genetic diversity in the region. When populations were compared for agronomic and morphologic traits, the best populations were between altitudes of 251 and 500 m. It was observed that all populations had a spreading growth habit, except for 05TA01, 05TA02, and 60ER01 (semi-erect) and 60TU02 (semi-spreading). The results suggested that new grazing, forage types, and disease resistant WBT varieties may be bred from the studied populations.