196 THE CACTACEAE. 



This species has long been passing under the name of Opuntia rutila Nuttall (Torrey and 

 Gray, Fl. N. Amer. i : 555. 1840). Dr. Engelmann referred it there in the Report of Simp- 

 son's Expedition (page 442), and again in the Botam^ of CaHfornia, with the remark that 

 "this plant seems to be Nuttall's long lost 0. rutila." And while it is true that the identi- 

 fication of Nuttall's plant is still doubtful, it seems improbable that this reference is correct. 



Fig. 242. — Opuntia erinacea. 



for the description does not agree with that of the above, and the original station of 0. rutila 

 in Wyoming is far removed from the other; keen collectors like A. Nelson and V. Bailey, who 

 have searched for the plant for us, have failed to find it in Wyoming. We suspect that 0. 

 rutila will prove to be 0. polyacantha. 



Opuntia ursina, which comes from the Mojave Desert, seems to be only a slender 

 form with long weak spines. This is known in the trade as the California grizzly bear cac- 

 tus. Alverson has described it as follows : "This curious plant is covered with tawny white 



