926 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



26. Echinocereus weinbergii Weing. Monatsschr. Kakteenk. 22: 83. 1912. 

 Probably a native of Mexico, but known only from cultivated plants. 



Very stout, usually simple, at first globose, becoming conical, at least in 

 cultivation, 13 cm. in diameter ; ribs 15, acute, more or less undulate ; areoles 

 elliptic, approximate; radial spines 9 to 12, pectinate, 3 to 12 mm. long, at 

 first vrhite or rose but in age yellowish ; central spines none ; flowers diurnal, 

 3.6 cm. broad, rose-colored ; inner perianth segments in several series, 1.5 to 

 3 cm. long, 4 to 5 mm. broad, lanceolate, acuminate. 



27. Echinocereus pectinatus (Scheidw.) Engelm. in Wisliz. Mem. North. Mex. 

 109. 1848. 



Echinocactus pectinatus Scheidw. Bull. Acad. Brux. 5: 492. 1838. 



Echinocactus pectiniferus Lem. Cact. Hort. Monv. 25. 1839. 



Cereus pectinatus Engelm. in A. Gray, PI. Fendl. 50. 1849. 



Central Mexico ; type from Villa del Penasco. 



Plants simple, erect, cylindric, 10 to 15 cm. long, 3 to 6 cm. in diameter, al- 

 most hidden by the many short interlocking spines ; ribs 20 to 22, usually 

 straight ; areoles approximate, but not touching one another, elliptic, 3 mm. 

 long ; radial spines about 30, pectinate, usually much less than 10 mm. long, 

 white or rose-colored, the colors more or less in bands about the plant ; cen- 

 tral spines several, more or less porrect ; flowers purplish, 6 to 8 cm. long ; 

 areoles on ovary and flower tube felted, very spiny; fruit spiny, becoming 

 naked, 2 to 3 cm. in diameter. 



28. Echinocereus scopulonim Britt. & Rose, Cactaceae 3: 30. 1922. 

 Sonora and Sinaloa ; type from Guaymas, Sonora. 



Stems single, cylindric, 10 to 40 cm. long, nearly hidden by the closely set 

 spines ; ribs 13 or more, low, somewhat tuberculate ; areoles circular, devoid 

 of wool (at least in areoles of the previous year) ; spines highly colored, 

 pinkish or brownish with blackish tips, in age, however, gray and stouter; 

 radials somewhat spreading; centrals 3 to 6, similar to the radials; flowers 

 with a delicate rose perfume, widely spreading when fully expanded, 9 cm. 

 broad ; tube 2 cm. long, broadly funnelform, bearing greenish tubercles ; inner 

 perianth segments 4 cm. long, rose or purplish rose, much paler on the out- 

 side, sometimes nearly white, oblanceolate to spatulate, erosely dentate, acute. 



29. Echinocereus roetteri (Engelm.) Riimpler; Forst. Handb. Cact. ed. 2. 829. 

 1885. 



Cereus roetteri Engelm. Proc. Amer. Acad. 3: 345. 1856. 



Ecliinocereus kunzei Giirke, Monatsschr. Kakteenk. 17: 103. 1907. 



Chihuahua. Texas and New Mexico ; type from El Paso. 



Cespitose, or perhaps sometimes simple and occasionally budding above, 10 

 to 25 cm. high ; ribs 13, straight, more or less undulate ; areoles circular, or a 

 little longer than broad, about 1 cm. apart ; radial spines 15 to 17, acicular, 

 about 1 cm. long, white or purplish ; central spines 1 to 5, not in a single row, 

 a little stouter but scarcely longef than the radials; flowers appearing below 

 the top of the plant, 6 to 7 cm. long, light purple; outer perianth segments 

 greenish yellow ; inner perianth segments oblanceolate, acute, 3 to 4 cm. long ; 

 ovary and fruit spiny. 



30. Echinocereus chlorophthalmus (Hook.) Britt. & Rose, Contr. U. S. Nat. 

 Herb. 16: 242. 1913. 



Echinocactus chlorophtlialmus Hook, in Curtis's Bot. Mag. 74: pi. JfSlS. 



1848. 

 Known only from the type locality. Real del Monte, Hidalgo. 



