446 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



The plant here called Opuntia engelmanni has been referred to under the name of 

 Opuntia engelmanni cyclodes Engelm. & Bigel. in one or two. publications of recent 

 years. That plant was first collected near Anton Chico, New Mexico, and Doctor 

 Engelmann separated it on the characters of small, globose fruit with larger seeds 

 than the species and fewer and shorter spines on the joints. The plants from southern 

 New Mexico match almost exactly, so far as spine characters go, material from near 

 the city of Chihuahua, and fruit of the New Mexican plant is never globose but ellip- 

 soid to slightly obovoid, about twice as long as broad. 



25. Opuntia stenochila Engelm. Proc. Amer. Acad. 3: 296. 1856. 

 Opuntia mesacantha stenochila Coulter, Contr. U. S. Nat. Herb. 3: 430. 1896. 

 Type locality: Canyon near Zuni, New Mexico. 



Range: Known only from the original collection by Bigelow. We have seen no 

 material of this species. 



26. Opuntia cymochila Engelm. & Bigel. Proc. Amer. Acad. 3: 295. 1856. 



Type locality: "Along the Canadian River east of the Llano Estacado, and on that 

 plain," Texas. 

 Range: Eastern New Mexico and the Panhandle region of Texas. 

 New Mexico: Nara Visa; Lakewood; Knowles. Lower and Upper Sonoran zones. 



27. Opuntia tenuispina Engelm. Proc. Amer. Acad. 3: 294. 1856. 

 Type locality: Sandhills near El Paso, Texas or Chihuahua. 

 Range: Western Texas, southern New Mexico, and adjacent Mexico. 



New Mexico: Rio Mimbres; Deming; Mesilla Valley. Lower Sonoran Zone. 

 This is the most common species in the lower Rio Grande Valley on the heavier soils. 



28. Opuntia toumeyi Rose, Contr. U. S. Nat. Herb. 12: 402. 1909. 

 Type locality: Tucson, Arizona. 



Range: Southern New Mexico and Arizona, probably in adjacent Mexico. 

 New Mexico : North of Kellys Ranch, west of Frisco and north of Alma; Lordsburg. 

 Low mountains, in the Lower Sonoran Zone. 



29. Opuntia chihuahuensis Rose, Contr. U. S. Nat. Herb. 12: 291. 1909. 

 Opuntia mesacantha sphaerocarpa Coulter, Contr. U. S. Nat. Herb. 3: 431. 1896. 

 Type locality: Santa Eulalia, near Chihuahua, Mexico. 



Range: Western Texas and central and southern New Mexico to Chihuahua. 



New Mexico: Organ Mountains; Ancho. Dry hills, in the Lower Sonoran Zone. 



The New Mexican specimens exactly match the type specimen of Opuntia chihua- 

 huensis and also match a specimen determined as 0. mesacantha oplocarpa Coulter by 

 Doctor Coulter himself. We have cultivated the plant in the garden at the Agricul- 

 tural College for years and have generally called it Opuntia camanchica Engelm., 

 although with some doubt in our minds, because we were not certain as to what that 

 species really is. Recently in the type locality of 0. camanchica it was possible to see 

 the plant growing in its native habitat all the way from the "Llano Estacado, at the 

 base of the hills * * * * to the Tucumcari hills," where it is everywhere the 

 common species. The plant from that region is darker green than that of the mesas 

 about the Agricultural College; its joints are slightly smaller, but the spines are much 

 the same; the habit of the plant is the same. It will be possible to determine the differ- 

 ences now, since we have the two growing side by side in the garden. 



30. Opuntia camanchica Engelm. & Bigel. Proc. Amer. Acad. 3: 293. 1856. 

 Type locality: Llano Estacado, on the upper Canadian River, Texas. 

 Range: Eastern New Mexico and northwestern Texas. 



New Mexico: Foot of Tucumcari Mountain; hills near Tucumcari. Upper Sono- 

 ran Zone. 



