Crepis occidentalis subs. costata
The major distinguishing characteristic of subsp. costata appears to be the relatively large, dark or black setae on the phyllaries. As defined by E. B. Babcock (1947), subsp. costata is a series of polyploid apomictic forms that are difficult to distinguish from subsp. occidentalis, as well as other species such as C. intermedia and C. bakeri. Reports for Arizona and South Dakota were not confirmed for this treatment.