450 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



All of the New Mexican material that we have seen is to be referred to Mamillaria 

 heyderi rather than the subspecies hemisphaerica, if the character which gives rise to 

 the name lb corn Ldered. The New Mexican plant is always flat-topped, with more or 

 i i ii Innate thickened root. It is not infrequently even larger than described. 



7. Mamillaria dasyacantha Engelm. Proc. Amer. Acad. 3: 268. 1856. 

 Ti ii; locality: "El Paso and eastward," Texas. 



Range: Western Texas to southern Arizona and adjacent Mexico. 

 New Mexico: Big Hatchet Mountains; Kingston; Lake Valley; Mogollon Creek. 

 Dry mountains, in the Lower and Upper Sonoran zones. 



8. Mamillaria macromeris Engelm. in Wisliz. Mem. North. Mex. 97. 1848. 



Type locality: Sandy soil near Dona Ana, New Mexico. Type collected by 

 Wislizenus. 



Range: Southern New Mexico to western Texas and Chihuahua. 



New Mexico: Dona Ana; Parkers Well; plains south of White Sands; Tortugas 

 Mountain. Mesas and sandy soil, in the Lower Sonoran Zone. 



One of the commonest Mamillarias of the southern part of the State, growing on sandy 

 mesas, forming rounded clumps sometimes almost a meter in diameter. The indi- 

 vidual plants are frequently 20 cm. long, fully half of the length being under ground. 

 They are rather dark green; the tubercles are large, the groove never reaching the 

 summit and sometimes wanting in young plants; the spines are long, the radials dull- 

 colored and often bent, the centrals dark, almost black, slender but stiff. The flowers 

 are a bright rose purple, sometimes lighter, often turning lavender; they are large, 5 

 cm. long or more and opening as wide, and usually are produced in profusion in the 

 middle of the summer. The species is a very desirable one for cultivation 



9. Mamillaria scheerii Miihlenpf. Allg. Gartenz. 15: 97. 1847. 

 Type locality: Mexico. 



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



New Mexico: Lordsburg; mesa near Agricultural College. Gravelly mesas and in 

 the mountains, in the Lower Sonoran Zone. 



Only 4 or 5 plants have been found around the Agricultural College. 



The flowers are 5 or 6 cm. long and of a peculiar bronze or brownish yellow, different 

 from most of our other Cactaceae. The single plants sometimes reach a height of 15 

 cm. and almost as great a diameter, being the largest single Mamillaria plants found 

 in New Mexico. The tubercles in such plants are 25 mm. long, and are distant, 

 spreading, and conic; the central spines are stout, one of them more or less curved 

 downward at the tip but not hooked. The fruit is green, pulpy, irregularly clavate 

 or obovato, with numerous brownish red seeds. It is one of the most interesting of 

 the New Mexican Mamillarias for pot culture. 



10. Mamillaria tuberculosa Engelm. Proc. Amer. Acad. 3: 268. 1856. 

 Mnmillaria strobiliformis Scheer in Salm-Dyck, Cact. Hort. Dyck. 104. 1850, not 



Miihlenpf. 1848, nor Engelm. 1848. 



Type locality: "From the Pecos to Leon Springs, Eagle Springs, and El Paso, on 

 the higher mountains," Texas. 



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



New Mexico: Tortugas Mountain; Van Pattens; near Hillsboro. Low, dry moun- 

 tains, in the Lower and Upper Sonoran zones, mostly on limestone soil. 



This little plan), with its dense coat of white radial spines and dusky-tipped cen- 

 trals, its proliferous habit, its tuberculate base, its small pink flowers, and its bright 

 red, tart fruit, is one of the commonest species of the southern part of the State, where 

 it is found growing in the crevices of limestone rocks. 



