Abstract
Lathyrus pisiformis belongs to the most endangered plants in the Czech Republic. However, our knowledge of habitat requirements and population biology of this rare species is very insufficient.
This work was focused on basic characteristics of two localities of this species in the Czech Republic: soil, phytosociology, shading at localities, and some basic parameters of population biology (number of stems, seeds etc.) between the years 2007 and 2011 were analyzed.