FLOWERING PLANTS AND FERNS OF ARIZONA 601 



3. Echinocactus polycephalus Engelm. and Bigel. in Engelm., Amer. 



Acad. Arts and Sci. Proc. 3: 276. 1856. 



Mohave and Yuma Counties, desert regions at low altitudes, flower- 

 ing February and March. Arizona, southern California, and north- 

 western Sonora. 



In this speeies, and in E. vera nth em aides, the plant is normally 

 many-stemmed, forming mounds. 



4. Echinocactus covillei (Britt. and Rose) Berger, Kakteenkunde. 



238. 1929. 



Ferocactus covillei Britt. and Rose, Carnegie Inst. Wash. Pub. 

 248. 3: 132. 1922. 



Pinal, Maricopa, and Pima Counties, 1,500 to 4,500 feet, June to 

 August. Arizona and northern Sonora. 



5. Echinocactus wislizeni Engelm. in Wisliz., Mem. North. Mex. 



96. 1848. 



Ferocactus wislizeni Britt. and Rose, Carnegie Inst. Wash. 



Pub. 248. 3: 127. 1922. 

 ? Echinocactus emoryi Engelm. in Emory, Mil. Reconn. 157. 



1848. 



Gieenlee and Cochise Counties to Maricopa and Pima Counties, up 

 to at least 4,500 feet, July to September. Western Texas, southern 

 New Mexico, Arizona, and northern Mexico. 



This species (pi. 23) and the preceding are the 2 largest barrel cacti 

 in Arizona. A specimen 11 feet high has been called to the authors' 

 attention by Frank A. Thackery. 



6. Echinocactus lecontei Engelm., Amer. Acad. Arts and Sci. Proc. 3: 



274. 1856. 



Ferocactus lecontei Britt. and Rose, Carnegie Inst. Wash. Pub. 

 248. 3: 129. 1922. 



Mohave, Maricopa, Pinal, Pima, and Yuma Counties, up to 3,500 

 feet, April and May. Southern Utah to Baja California, Arizona, 

 and Sonora. 



This species appears to intergrade with, or simulate, E. acanthodes. 



7. Echinocactus acanthodes Lemaire, Cact. Gen. Nov. Sp. 106. 1839. 



Ferocactus acanthodes Britt. and Rose, Carnegie Inst. Wash. 



Pub. 248. 3: 129. 1922. 

 Ferocactus rostii Britt. and Rose, Carnegie Inst. Wash. Pub. 



248. 3: 146. 1922. 

 Echinocactus hertrichii Weinberg, Desert Plant Life 1 : 40. 1929. 



Yuma County, up to 3,000 feet, April to June. Southern Nevada 

 to Arizona and Baja California. 



8. Echinocactus johnsoni Parry ex Engelm. in King, Geol. Expl. 



40th Par. 5: 117. 1871. 



Ferocactus johnsoni Britt. and Rose, Carnegie Inst. Wash. 

 Pub. 248. 3: 141. 1922. 



Mohave and Yuma Counties, up to 3,000 feet, April. Southwestern 

 Utah to California, and Arizona. 



