46 



THE CACTACEAE. 



ous, straight, rigid; radial spines 15 to 20, 10 to 30 mm. long, whitish; inner spines 3 to 6, stouter 

 than the radial ones, deep brown above; flowers large, 5 to 7 cm. broad, rose-colored; outer perianth- 

 segments 30 to 40, linear-subulate, with fimbriate margin; inner perianth-segments 40 to 50, lan- 

 ceolate-linear, attenuate ; stigma-lobes 8 to 10, white ; fruit oval, green ; seeds compressed, light brown, 

 pitted. 



Type locality: Northern Arizona. 



Distribution: Northern Arizona, especially along the Upper River of the Grand Canyon, 

 and perhaps also in southern Utah.* 



Mamniillaria arizonica Engelmann, when first described, was a complex. Engelmann 

 states that it was found "on rocky and sandy soil in northern Arizona from the Colorado 

 eastward (Coues, Palmer, F. Bischoff) and into southern Utah (J. E. Johnson) ; probably in 

 southeastern California." Engelmann afterwards described Johnson's plant from Utah 

 as ]\I. chlorantha and the California plant is doubtless his M. descrti. We have in the U. S. 

 National Herbarium Palmer's specimen from Arizona but we have not seen the plant of 

 Coues nor of Bischoff. 





Figs. 44 and 45. — Coryphantha deserti. 



The northern range of this species is ver}^ uncertain. Engelmann extended it into 

 southern Utah. 



Plate V, figure 5, shows a plant sent by M. A. H. Spencer from 

 the Grand Canyon, Arizona, in May 1907, which afterwards flowered 

 in Washington. 



34. Coryphantha deserti (Engelmann). 



MammiUaria deserti Engelmann, Bot .Calif. 2: 449. 1880. 

 Cactus radiosiis deserti ConXtQX, Contr. U. S. Nat. Herb. 3: 121. 1894. 

 Cactus radiosus alversonii Coulter, Contr, U. S. Nat. Herb. 3: 122. 1894. 

 MammiUaria alversouii Zeissold, ilonatsschr. Kakteenk. 5: 70. 1895. 

 MammiUaria radiosa alversonii Schumann, Gesamtb. Kakteen 481. 1898. 

 MammiUaria radiosa deserti Schumann, Gesamtb. Kakteen 481. 1898. 



Solitary or cespitose, usually cylindric, sometimes 2 dm. high, 6 to 9 cm. 

 in diameter, densely covered \\'ith spines; radial spines white except at tip, 



* Our Utah reference is based on some detached flowers collected by M. E. Jones and a barren plant sent by 

 Dr. C. D. Marsh in 1922. Both collections came from above Salina. 



Fig. 46. — Flower of 

 C. deserti. 



