WOOTON AND STAKDLEY— PLOEA OF NEW MEXICO. 455 



Spines 3 to 6, mostly 3, shorter and not so stout. 9. E. triglocMdiatus. 



Spines more slender though rigid, mostly terete, 



more numerous in the areole (except in E. 



paucispinus). 



Centrals none or sometimes 1; radials 3 to 6; 



spines all terete or but slightly flattened, 



stout for the group 10. E. paucispinus. 



Centrals 1 to several, mostly 3 to 5 or 6; radials 

 8 to 16, mostly 10 to 13; spines often flat- 

 tened or angled. 

 Centrals mostly 6; flowers small, the petals 



acute 11. E. neomexicanus. 



Centrals 3 to 5, mostly 4; flowers larger; 

 petals obtuse. 

 Centrals stout, terete, usually gray or 

 pinkish gray when young, dark 

 gray in age, 15 to 20 mm. long.. 12. E. rosei. 

 Centrals more slender, yellowish to 

 gray or darker. 

 Spines short, mostly yellowish; 

 centrals 14 to 40 mm. long, 

 mostly about 25 mm. ; plants 

 rounded or somewhat de- 

 pressed at the apex 13. E. coccineus. 



Spines much longer, mostly dark, 

 the centrals 25 to 80 mm. 

 long, commonly about 50 

 mm.; plants conic at the 

 apex 14. E. conoideus. 



Echinocereus hexaedrus (Engelm.) Eumpl. from near Zuni, known only from the 

 type locality, is probably only a form of E. gonacanthus, orginally from the same 

 region, where it is fairly common. Wliat the plant may be which Doctor Coulter 

 refers to E. octacanthus (Fendler's 272, in part, from Santa Fe) we are unable to say, 

 but it is likely to be either a form of E. paucispinus or an aberrant E. coccineus. 

 Schumann is certainly incorrect in reducing E. gonacanthus and E. triglocMdiatus to 

 E. paucispinus; the two angular-spined species may be the same, although this is 

 doubtful, but E. paucispinus is more closely related to the E. piolyacanthus grouiD, not- 

 withstanding its few spines. 



1. Echinocereus chloranthus (Engelm.) Rumi^l. in Forst. Handb. Cact. ed. 2. 



814. 1886. 

 Cereus chloranthus Engelm. Proc. Amer. Acad. 3: 278. 1856. 

 Type locality: "Stony hills and mountain sides near El Paso." 

 Range: Southern New Mexico, trans-Pecos Texas, and adjacent Mexico. 

 New Mexico: Tortugas Mountain; Organ Mountains; San Mateo Peak; Queen; 

 Cooks Peak; Rincon; Lake Valley. Limestone hills, in the Lower Sonoran Zone. 



2. Echinocereus viridiflorus Engelm. in Wisliz. Mem. North. Mex. 7. 1848. 

 Cereus viridiflorus Engelm. in A. Gray, Mem. Amer. Acad. n. ser. 4: 50. 1349. 

 Type locality: Prahies on Wolf Creek, New Mexico. Type collected- by Wislize- 



nus in 1846. 



Range: Southern Wyoming to New Mexico and western Texas. 



New Mexico: Pecos; Colfax; west of Santa Fe; Organ Mountains; White Moun- 

 tains; Sierra Grande; Nara Vija. Upper Sonoran Zone. 



