WOOTON AND STANDLEY — FLORA OF NEW MEXICO. 445 



he worked with the cacti of that region more than almost any other person imtil very 

 recently, and knew American species better than anyone else of his day. 



Well grown plants of this are suberect, about 1 meter high or even more. Many 

 times the plants are smaller and sometimes, though not usually, they are spreading. 

 It may be recognized readily by its thin, mostly circular, reddish joints and its long, 

 nearly black spines. Occasional joints have no spines but abimdant brown bristles. 

 If groMTi where it gets plenty of water the joints grow much thicker, and lose their 

 red color, becoming bluish green and glaucous. 



19. Opuntia dulcis Engelm. Proc. Amer. Acad. 3: 291. 1856. 

 Type locality: Near Presido del Norte, Texas. 



Range: Western Texas to southern New Mexico. 



New Mexico: Mesilla Valley; Guadalupe Mountains; Mangaa Springs. Lower 

 Sonoran Zone. 



This is the plant referred to as Opuntia laevisf in Griffiths and Hare's bulletins 

 on cacti. The Mangas Springs specimens may be true 0. laevis. The plant is intro- 

 duced in the Mesilla Valley and is widely cultivated for hedges. It is said to have 

 come from Chihuahua. 



20. Opuntia lindheimeri Engelm. Bost. Joum. Nat. Hist. 5: 207. 1845. 

 Type locality: About New Braimfels, Texas. 



Range : Western Texas to southern New Mexico. 



New Mexico: Guadalupe Moimtains (Wooton 5505). Dry hills. 



21. Opxintia phaeacantha Engelm. Mem. Amer. Acad. n. ser. 4: 352. 1849. 



Type locality: "On rocky hills about Santa Fe, and on the Rio Grande," New 

 Mexico. Type collected by Fendler. 



Range: Colorado and New Mexico. 



New Mexico: Santa Fe; Puertecito; Gallup; Flora Vista; Chamita; near Magda- 

 lena; Rio Hondo; Gallinas Mountains. Dry hills, in the Upper Sonoran Zone. 



This is the common suberect plant of the mountains and plains of the northern 

 part of the State. When well grown it is often a meter high and where it gets abun- 

 dance of water its joints are rather bluish green and thick and have dark spines. Where 

 it is drier, the joints are often yellowish green and the spines lighter in color. Yoimg 

 plants are much smaller than the key requires and seem to be procumbent. 



22. Opuntia •wootoni Griffiths, Rep. Mo. Bot. Gard. 21: 171. 1910. 

 Type locality: Organ Mountains, New Mexico. 



Range: Known so far only from the Organ Mountains and Tortugas Mountain, 

 southern New Mexico, in the Lower and Upper Sonoran zones. 



This is perhaps most closely related to Opuntia engelmanni, having its spines 

 arranged much as in that species, but the joints are narrowed at the top, being ovate 

 or oval, and the long stout spines are yellow at the tip and reddish or brownish 

 at the base. 



23. Opuntia dillei Griffiths, Rep. Mo. Bot. Gard. 20: 83. 1909. 



Type locality: San Andreas Canyon of the Sacramento Mountains, New Mexico, 

 about 5 miles south of Alamogordo. 



Range: Known only from type locality, in the Upper Sonoran Zone. 

 The large, circular, thick joints with few or no spines are characteristic. 



24. Opiintia engelmanni Salm-Dyck; Engelm. Proc. Amer. Acad. 3: 291. 1856. 

 Type LOCALrrY: Near Chihuahua, Mexico. 



Range: Western Texas and southern New Mexico to Mexico. 



New Mexico: Mesa west of Organ Mountains; Organ Mountains; Dog Spring; 

 Lordsburg; Hatchet Mountains; east of Hillsboro; Red Rock; Deming. Lower and 

 Upper Sonoran zones. 



