438 EXPLORATIONS ACROSS TEE GREAT BASIN OP UTAH. 



genera] appearance, the habitus, of a cactus plant, not necessarily indicates its real 

 affinities. Not only is it a true Echiwratin.% notwithstanding every appearance of a 

 MamiUaria, but it is, moreover, closely allied in all Its essential characters to the very 

 compact Krh. infnlr.rtns, En-elm., ( \ Bound, p. 27, t. 34, in which all traces of tuber- 

 cules are lost iii the straight ribs. It has the same small flowers and the same small 

 dry fruit, containing few large seeds, of similar structure, though not entirely the same 

 arrangement of the spines. 



Full-grown specimens of our plant are 3-5 inches high and 3-4 inches in diam- 



being most prominent. They are (l-S linos long, at base somewhat quadrangular, 

 6-7 lines wide in the vertical and 4-5 lines in the transverse diameter, becoming sub- 

 cylindric upward ; areola- 3-4 lines long, a little more than half as wide. The fruit- 

 bearing tubercules are rather stouter and shorter. Exterior spines 4-6 lines long, 

 whitish; interior ones spreading, stouter, and a little longer (5-7 lines long), yel- 

 lowish and upward deep brown or black ; no truly central spine. In the very young 

 plant, the spines, 18-20 in number and only 1-1. J lines in length, are all radiating, 





the areola 



■o,l abov. 



of the plant 



long before 





3ter, externally greenish- 



ales, sometimes with 1 or 2 small spines in their axils. The 

 an irregular lateral slit ; falling off; its base remains attached 

 case in many (or all ? or onlv all the drv-fruited ?) Evlhwcucti, 

 d opening (see t. 2, f. 5). Seeds 11 lines long in the longest 

 minute close-set tubercles. The young seedling shows erect. 



•seem >pi 

 the sum 





