Some Echinocerei of New Mexico 



I'aul Carpknter Standi. i;v 





Among the commonest of the cacti that grow in the southern 

 part of New Mexico are the scarlet-flowered Echinocerei. They 

 are abundant upon the sandy mesas that lie above the valley of 

 the Rio Grande and are frequently seen in the mountains that rise 

 here and there above the mesas. They are never found in the 

 valley of the river. To a botanist observing the plants it is evident 

 that a number of different forms are represented, for the plants 

 vary noticeably in habit, size, length and color of spines, and color 



and size of flowers. 



The writer spent some time during the spring of 1907 in a 

 study of these forms in an attempt to see how many species might 

 be represented or whether all the forms found might not be modi- 

 fications of one extremely variable species. The material for this 

 study consisted of something over a thousand separate plants 

 growing in the cactus garden of the New Mexico Agricultural 

 College. These plants were collected mostly upon the mesa lying 

 between the Rio Grande valley and the Organ Mountains. A few 

 were brought from the Organ Mountains. Several plants from the 

 type locality of Echinocereus co incus were also examined. In 

 addition to this living material, examination was made, through 



th 



w 



th 



Garden, and Dr. B. L. Robinson, of the Gray Herbarium, of the 

 dl "'ed material in the herbaria of these institutions, including the 

 ^Pe material of the three species here discussed. In addition to 

 the types a number of other interesting specimens collected by 



e early botanical explorers, some of them in this same region, 

 We re examined. 



As soon as the plants began blooming, about the middle of 



arch, the study of them was begun. Measurements were made 

 of over a thousand plants. These measurements included size 

 an d habit of plants, number of ridges, number and arrangement 



77 



M 



