This is a widespread variable Eurasian species; 2n = 14, 28, 42. There are few records from North America, and it does not seem to be increasing (FNA 24). B. ramosus was reported from Ky. by Britton (1901) and Anderson (1924), but no colls. have been located; Anderson cited F.T. McFarland #2194, June 19195, from Lexington [FAYE].