1014 MISC. PUBLICATION 4 2 3, U. S. DEFT. OF AGRICULTURE 



5. Cirsium rothrockii (A. Gray) Petrak, Bot. Tidsskr. 31: 68. 1911. 



Cnicus rothrockii A. Gray, Amer. Acad. Arts and Sci. Proc. 

 17: 220. 1882. 



Southern Navajo, Gila, and Cochise Counties (probably elsewhere), 

 4,000 to 6,000 feet, June to September, type from Arizona without 

 definite locality. Utah (?) and Arizona. 



Flowers rose-colored to carmine. 



6. Cirsium bipinnatum (Eastw.) Rydb., Fl. Rocky Mount. 1010, 



1068. 1917. 



Cnicus drummondii var. bipinnatus Eastw., Zoe 4: 8. 1893. 



Carrizo Mountains, Apache County, in a deep canyon (Standley 

 7401) near Tuba, Coconino County, where reported as common on 

 the desert (Clute 117), perhaps also in the Huachuca Mountains, 

 Cochise County (Wilcox in 1894, Goodding 1352), 5,000 to 6,000 feet, 

 June to August. Colorado, Utah, New Mexico, and Arizona. 



7. Cirsium nidulum (M. E. Jones) Petrak, Bot. Centbl. Beiheft. 35 2 : 



553. 1917. 



Cnicus nidulus M. E. Jones, Calif. Acad. Sci. Proc. ser. 2, 



5: 705. 1895. _ 

 ? Carduus rusbyi Greene, Acad. Nat. Sci. Phila. Proc. 1892: 



361. 1893. 



Cameron to Navajo Bridge and base of Navajo Mountain, eastern 

 Coconino County, 5,500 to 6,300 feet (Peebles 13009, 13929), north 

 rim of the Grand Canyon, 8,000 feet (Collom in 1940), perhaps also 

 in the Santa Rita Mountains, Pima County, 5,000 feet (Thornber 272), 

 June and July. Southern Utah, Nevada, and Arizona. 



Specimens intermediate between this species and C. rothrockii have 

 been collected at the Grand Canyon (MacDougal 174, A. E. Hitchcock 

 68). 



8. Cirsium arizonicum (A. Gray) Petrak, Bot. Tidsskr. 31: 68. 1911. 



Cnicus arizonicus A. Gray, Amer. Acad. Arts and Sci. Proc. 

 10: 44. 1874. 



Flagstaff region (Coconino County), Hualpai Mountain (Mohave 

 County), south to the mountains of Cochise and Pima Counties, 

 3,000 to 7,000 feet, frequent on rocky slopes, often in chaparral, 

 May to October, type probably from Cochise County. Utah (?) 

 and Arizona. 



In the Hopi Reservation, on the Kaibab Plateau, and at the Grand 

 Canyon, specimens intermediate between this species and C. nidulum 

 have been collected. Species 5 to 8 are closely related, and inter- 

 mediates, presumably of hybrid origin, are not infrequent. 



9. Cirsium pulchellum (Greene) Woot. and Standi., Contrib. U. S. 



Natl. Herbarium 19: 752. 1915. 



Carduus pulchellus Greene ex Rydb., Colo. Agr. Expt. Sta. Bui. 

 100:401. 1906. 



Hopi Indian Reservation, Navajo County (Zuck in 1897), Tuba, 

 Coconino County (Harrison and King 8709), perhaps also in Yavapai 

 and Gila Counties, 5,000 to 6,000 feet, June to August. Colorado, 

 Utah, New Mexico, and Arizona. 



