10 Cockerell New CocMebur from New Mexico. 



5| mm.), and the prickles much less numerous (about 25 to the bur) and 

 mostly stouter basally. Collected by the writer at Espanola, N. M. and 

 Las ,.Yegas, N. M. It occurs abundantly, always growing with X. 

 commune. 



Specimens of -X". c. wootoni have been sent to Prof. E. L. Green and to 

 Dr. P. A. Rydberg. The former said it was unknown to him, the latter 

 considered it a new species. 



It is, in fact, a species in the De Vriesian sense, of more than ordinary 

 interest. 



Las Vegas specimens sent to the U. S. National Herbarium may be 

 regarded as the types (No. 404186). Other specimens showing leaves 

 and flowers as well as burs, are in the Herbarium of the New York 

 Botanical Garden and the Herbarium of the New Mexico Agricultural 

 College. 



