968 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



brownish, the upper generally weaker, the 2 or 3 uppermost much weaker, 

 clustered closely together and very pale, some of them sometimes crowded 

 toward the center ; central spine solitary, very stout and erect or sometimes 

 curved or even hooked, yellow, 3.5 cm. long; all the larger spines somewhat 

 bulbous at the base ; flowers 5 to 6 cm. long, salmon-colored ; ovary 20 to 25 

 mm. long, bearing 4 to 7 minute caducous scales ; fruit narrowly oblong, 6 cm. 

 long ; seeds 3 mm. long, brown, shining. 



16. Coryphantha connivens Britt. & Rose, Cactaceae 4: 34. 1923. 

 Valley of Mexico, the type from Tlalpam. 



Globular or somewhat depressed, 8 to 10 cm. broad, somewhat woolly at the 

 crown at flowering time but becoming glabrate; spines all radial but of two 

 kinds, one kind spreading or curved backward, subulate, horn-colored, 5 or 6, 

 the others from the upper part of the spine areole, clustered, erect, or toward 

 the top connivent, acicular, black at tip, 8 to 10; flowers yellow, 6 to 7 cm. 

 broad; perianth segments narrowly oblong, acuminate; fruit greenish, oblong, 

 3 cm. long ; seeds brown, 2 mm. long. 



17. Coryphantha pectinata (Engelm.) Britt. & Rose, Cactaceae 4: 34. 1923. 

 Mammillaria pectinata Engelm. Proc. Amer. Acad. 3: 256. 1856. 



Northern Mexico. Texas. 



Usually simple, globose, 3 to 6 cm. in diameter; tubercles usually arranged 

 in 13 spirals ; upper tubercles 10 to 12 mm. long, about twice as long as the 

 lower ones ; areoles a little longer than broad ; spines 16 to 24, all radial, those 

 on the lower areoles appressed and often a little recurved, those from, the 

 upper part of the upper areoles 12 to 18 mm. long, connivent over the apex, 

 yellowish white with black tips; flowers yellow, 5 cm. long; ovary 6 to 8 mm. 

 long; fruit 12 mm. long. 



18. Coryphantha nickelsae (K. Brandeg.) Britt. & Rose, Cactaceae 4: 35. 1923. 

 Mammillaria nickelsae K. Brandeg. Zoe 5: 31. 1900. 



Nuevo Leon. 



Described as globular, densely cespitose, often 7 cm. high, pale green and 

 glaucous ; older plants becoming purplish ; tubercles almost hidden by the over- 

 lapping spines, rather broad at base, low, not densely arranged; spines 14 to 

 16, all radial (a few forming a small fascicle at the top of the groove), 

 slender, at first simply spreading but afterward bent back and interlaced with 

 those of the adjoining tubercles, S to 10 mm. long, at first j'ellowish at base 

 with dark tips, but afterwards bleaching; flowers described as bright yellow, 

 with a red center, 5 to 7 cm. broad ; fruit nearly globular, 5 to 7 mm. long, 

 green ; seeds small, brown. 



19. Coryphantha compacta (Engelm.) Britt. & Rose, Cactaceae 4: 36. 1923. 

 Mammillaria compacta Engelm. in Wisliz. Mem. North, Mex. 105. 1848. 

 Chihuahua, the type from Cosihuiriachi. 



Plants solitary, somewhat depressed, 3 to 6 cm. high, 5 to 8 cm. broad ; 

 tubercles in 13 rows, much crowded, 8 mm. long, sulcate above; radial spines 

 13 to 16, rigid, appressed, interwoven with adjacent ones, whitish, 10 to 20 mm. 

 long ; central spines usually wanting ; flowers 2 cm. long and broad, yellow ; 

 fruit oval ; seeds smooth and yellow. 



20. Coryphantha radians (DC.) Britt. & Rose, Cactaceae 4: 36. 1923. 

 Mammillaria radians DC. M6m. Mus. Hist. Nat. 17: 111. 1828. 

 Mammillaria impexicoma Lem. Cact. Aliq. Nov. 5. 1838. 

 Mammillaria daimonoceras Lem. Cact. Aliq. Nov. 5. 1838. 



Central Mexico. 



