68 



The West American Scientist. 



one arrive at correct conclusions relative to species and varieties, 

 and this none of our botanists have yet enjoyed- 



Near San Diego the genus is represented by E. viridescens 

 Nutt, usually a low, depressed plant of about thirteen ribs, with 

 pale straw-colored flowers and a slightly acid, pleasant fruit. 

 This is a maritime species or variety almost wholly restricted to 

 the immediate neighborhood of San Diego. 



ECHINOCACTUS CYLINDRACEUS. 



Echinocactus Orcuttii, Engelm., is found a little further to the 

 south and further inland from the coast. It differs in size, the 

 number of ribs (usually twenty-two to thirty) and in the young 

 plants, which are globose. It is inclined to grow in caespitose 

 clumps of fifteen to twenty cylindrical heads, around which the 

 ribs are often spirally inclined. It seems to form almost a con- 

 necting link between E. viridescens and E.cylindraceus, Engelm., 

 which latter was originally collected by Dr. Parry on the eastern 

 slopes ol the mountains bordering the Colorado Desert, in San 

 Diego county. Dr. Engelmann was at one time inclined to doubt 

 the right of E. cylindraceus to specific rank, as other botanists 

 are still inclined to doubt. In 1882, I found what I determined 

 was E. cylindraceus in the desert canons of Lower California, and 

 also west of the mountains near the San Rafael valley, and 

 Dr. Engelmann wrote that he concurred with me in that opinion. 

 This cactus was a fine cylindrical plant, encompassed by a fine net- 

 work of its slender, recurving white spines, with lemon-yellow 

 flowers. 



Echinocactus Lecontei, Engelm., is another species originally 

 credited to the Eastern slope of our mountains and to Arizona. 

 Hundreds of plants annually reach the European market under 

 this name, collected within the confines of the Colorado Desert, 

 which differ only in a slight degree from E. cylindraceus. This 

 form is more inclined to a grayish color, less flexible spines, and 

 perhaps to a more globose shape. The demand in Europe for 



