WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 441 
Further critical study of the genus will undoubtedly result in the recognition of 
many more species in this distribution area and in the better limitation of the species 
now recognized. 
A specimen from Gallup, collected October 20, 1896, by Ashmun we are unable to 
determine. Its spines suggest Opuntia cymochila, but the joints are orbicular or even 
broader than long. 
1. Opuntia brachyarthra Engelm. & Bigel. Proc. Amer. Acad. 3: 302. 1856. 
Opuntia fragilis brachyarthra Coulter, Contr. U. 8. Nat. Herb. 3: 440. 1896. 
Tyre tocauity: Inscription Rock, near Zuni, New Mexico. Type collected by 
Bigelow in 1853. 
Ranae: Known only from the type locality. 
As described, this is a small tumid-jointed plant, possibly related to O. arenaria or 
O. fragilis. It has not been collected in recent years. A specimen from Santa Fe, 
collected by Bigelow and referred to this species, may be Opuntia fragilis, as that 
species comes into the mountains a short distance north of Santa Fe. Possibly Doctor 
Coulter may have been right in considering Opuntia brachyarthra a subspecies of 
O. fragilis. Until further material of O. brachyarthra from the type locality can be 
studied, it is probably better to retain it as a species. 
2. Opuntia fragilis (Nutt.) Haw. Syn. Pl. Succ. Suppl. 82. 1819. 
Cactus fragilis Nutt. Gen. Pl. 1: 296. 1818. 
Type Locauity: ‘‘From the Mandans to the mountains, in sterile but moist situ- 
ations.”’ 
Rance: Wisconsin and British Columbia to Kansas and northern New Mexico. 
New Mexico: Lake La Jara; Tunitcha Mountains. Upper Sonoran Zone. 
3. Opuntia arenaria Engelm. Proc. Amer. Acad. 3: 301. 1856. 
TYPE LOCALITY: Sandy bottoms of the Rio Grande near El Paso, Texas or Chi- 
huahua. 
Rance: Southern New Mexico and western Texas. 
New Mexico: Mesquite Lake (Standley). Sandy soil, in the Lower Sonoran Zone. 
Joulter refers Fendler’s 7, 150, and 153 to this species and to New Mexico. Where 
they were obtained we have been unable to ascertain. Opuntia arenaria has such a 
limited distribution in the type locality and occurs in a habitat so different from the 
region about Santa Fe (where Fendler did most of his collecting) that we are inclined 
to doubt the accuracy of the reference. It is possible the plant may occur in the 
Rio Grande Valley west of Santa Fe, but even this is doubtful. The collection at 
Mesquite Lake is the only one made since the type was gathered. The plants are 
notatallabundant here. They grow on the dunes of pure sand about one of the lakes 
or oxbows formed in the old bed of the Rio Grande. 
4. Opuntia stanlyi Engelm. in Emory, Mil. Reconn. 157. f. 9. 1848. 
Type LocauiTy: On the Del Norte and Gila, New Mexico. Type collected by 
Emory. 
Rance: Southern New Mexico and Arizona and adjacent Mexico. 
New Mexico: Near Carlisle (Wooton). Lower Sonoran Zone. 
Opuntia stanlyi is a very distinct species with thick joints 10 to 12 em. long and 
3 to 4 cm. in diameter, with large tubercles and various spines. It forms beds often 
2 or 3 meters across and only 30cm. high orless. It grows on sandy mesas in the south- 
western part of the State, but is more common in Arizona. Our specimens are from 
very near the type locality. 
5. Opuntia grahami Engelm. Proc. Amer. Acad. 3: 304. 1856. 
TYPE LocaLity: Sandy bottoms of the Rio Grande near El Paso, Texas or Chi- 
huahua. 
