970 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM, 



Plants either solitary or in clusters, nearly globular or sometimes club- 

 shaped, 10 to 15 cm. in diameter, light green ; tubercles rather short, closely 

 set; radial spines about 15, spreading, slender, 10 to 15 mm. long, grayish or 

 whitish ; central spines 1 to 4, reddish to black, the 3 upper ones when present 

 ascending and those near the top of the plant connivent, the lowest central 

 stouter than the others, 2 to 2.5 cm. long, porrect or curved downward ; flowera 

 4 cm. long; outer perianth segments greenish or tinged with red, the inner 

 pale yellow. 



26. Coryphantha pallida Britt. & Rose, Cactaceae 4: 40. 1923. 

 Puebla, the type from Tehuacan. 



Plant body either solitary or in clusters of 10 or more, globular, 12 cm. in 

 diameter or less, bluish green ; tubercles in 13 rows, short and thick, closely 

 set; radial spines 20 or more, white, appressed; centrals usually 3, but some- 

 times more, the upper more or less ascending, the lower porrect or curved 

 downward, with the tips black, or sometimes black throughout ; flowers often 7 

 cm. long and nearly as broad ; outer perianth segments narrow, greenish yel- 

 low, with a reddish stripe on the back ; inner perianth segments pale lemon- 

 yellow, broader than the outermost, acuminate; ovary bearing a few narrow 

 scales; fruit greenish brown, 2 cm. long; seeds brown, shining. 



27. Coryphantha pycnacautha (Mart.) Lem. Cact. 35. 186S. 



"i Mammilla ria latimamma DC. Mem. Mus. Hist. Nat. 17: 114. 1828. 



Mammillaria pycnacautha Mart. Nov. Act. Nat. Cur. 16: 325. 1832. 



1 Mammillaria acanthostephes Lelim. Allg. Gartenz. 3: 228. 1835. 



Mammillaria arietina Lem. Cact. Aliq. Nov. 10. 1838. 



MammiHaria scepontocentra Lem. Cact. Hort. Monv. 43. 1839. 



Mammillaria winkleri Forst. Allg. Gartenz. 15: 50. 1847. 



Oaxaca, the type from Oaxaca City. 



Plant body solitary, globular to cylindric, about 8 cm. high ; tubercles broad, 

 grooved above, glaucous-green ; radial spines 10 to 12, slender, 10 to 16 mm. 

 long; central spines about 4, stouter than the radials, about 25 mm. long, 

 more or less curved backward, usually black ; flowers from near the center 

 of the plant, 25 mm. in diameter, yellowish ; perianth segments numerous, 

 very narrow. 



28. Coryphantha durangensis (Riinge) Britt. & Rose, Cactaceae 4: 42. 1823. 

 Mammillaria durangensis Riinge ; Schum. Gesamtb. Kakt. 478. 1898. 

 Northern Mexico ; type from Villa Lerdo, Durango. 



Plants solitary or in small clusters, short-cylindric, 10 cm. long or less, 

 somewhat glaucous ; tubercles rather prominent, ' in 5 to 8 series, somewhat 

 compressed dorsally, very woolly in the axils ; radial spines G to 8, acicular, 

 spreading, 1 cm. long or less ; central spines solitary, often erect, those of the 

 uppermost areoles connivent, black ; flowers about 2 cm. long, when fully ex- 

 panded 2.5 to 4 cm. broad ; outer perianth segments dark purple or with only 

 a purple stripe down the center ; inner perianth segments cream-colored to 

 pale lemon-yellow ; fruit globular, 5 to 8 mm. in diameter, naked, greenish ; 

 seeds brown, about 1 mm. broad. 



29. Coryphantha neomexicana (Engelm.) Britt. & Rose, Cactaceae 4: 45. 1923. 

 Mammillaria vivipara radiosa neomexicana Engelm. Proc. Amer. Acad. 3: 



269. 1856. 

 Mammillaria neomexicana A. Nels; Coult. & Nels. Man. Rocky Mount. 237. 



1909. 

 Chihuahua. Texas and New Mexico. 



