

Ramaley and Dodds: Two species of Crataegus 583 



much-lumped group as a variety under an eastern species. The 

 Rocky Mountain species of Crataegus are restricted in distribution 

 to canyon mouths and gulches of the lower foothills. They do 

 not occur on the plains. Hence it seems best to consider them as 

 specifically distinct from eastern species. The discontinuous dis- 

 tribution in itself would be almost sufficient ground for such sepa- 

 ration, but the characters of our Colorado species are so good that 

 they certainly deserve separate treatment. 



C. occidentalis and C. coloradeusis may be distinguished with 

 ease in the field or the herbarium, whether flowering or fruiting 

 specimens are examined. Indeed, with neither flowers nor fruits it 

 is an easy matter to separate them from each other, although not 

 so easy to distinguish C. occidentalis from some other closely re- 

 lated forms. 



University of Colorado, 

 Boulder, Colo. 



