928 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



dark gray; radial spines about 12, spreading, acicular; central spines usually 

 4, very much stouter, more or less flattened, erect or porrect, the lowest one 

 decidedly so, sometimes 8 cm. long ; flowers purplish, about 5 cm. long ; areoles 

 on ovary and tube closely set, filled with pale acicular spines and long white 

 wool; fruit globular, 3 cm. in diameter, spiny; seeds black, tuberculately 

 roughened. 



For an illustration of this species see Contr. U. S. Nat. Herb. 16: pi 12^. 



86. Echinocereus hempelii Fobe, Monatsschr. Kakteenk. 7: 187. 1897. 



Native of Mexico, but known only from cultivated plants. 



Plant, so far as known, simple, erect, 15 cm. long or more, 6 to 7 cm. in 

 diameter, dark green ; ribs 10, strongly tuberculate ; radial spines 6, spreading, 

 white with brown tips, acicular, 1 cm. long or less ; central spines none ; 

 flowers from near the top of plant, 6 to 8 cm. broad, violet; inner perianth 

 segments about 14, loosely arranged, oblong, 3 cm. long, strongly toothed above ; 

 ovary bearing conspicuous red scales, spiny. 



37. Echinocereus merkeri Hildmann ; Schum. Gesamtb. Kakt. 277. 1898. 

 Cereus merkeri Berger, Rep. Mo. Bot. Gard. 16: 81. 1905. 

 Durango, Coahuila, and San Luis Potosl. 



Cespitose ; joints erect, 12 to 15 cm. in diameter, light green ; ribs 8 or 9, 

 sinuate; radial spines 6 to 9, white, shining; central spines 1 or rarely 2. 

 often yellowish, larger than the radials, red at base; flowers purple, about 

 6 cm. long ; inner perianth segments short-oblong, 3 cm. long, rounded at apex, 

 sometimes mucronate ; scales on ovary 2 to 3 cm. long, ovate, acuminate, 

 bearing 2 to 5 long spiny bristles in their axils. 



38. Echinocereus fendleri (Engelm.) Riimpler ; Forst. Handb. Cact. ed. 2. 

 801. 1885. 



Cei-eus fendleri Engelm. in A. Gray, PI. Fendl. 50. 1849. 



Sonora and Chihuahua. Texas to Utah and Arizona ; type from Santa Fe, 

 New Mexico. 



Cespitose; stems about 8, ascending or erect, 10 to 30 cm. long, 5 to 7.5 cm. 

 in diameter ; ribs rather prominent, 9 to 12, somewhat undulate ; spines very 

 variable as to color, length, and form ; radial spines 5 to 10, more or less 

 spreading, 1 to 2 cm. long, acicular to subulate; central spine solitary, usually 

 porrect, 4 cm. long or less, dark-colored, often black -bulbose at base ; flowers 

 borne at the upper part of the plant, 10 cm. broad when fully expanded, 

 but sometimes smaller, deep purple; iimer perianth segments spatulate, 

 3 to 4 cm. long, acute, the margin sometimes serrulate; ovary deep green, its 

 areoles bearing white felt and white bristly spines ; fruit ovoid, 2.5 to 3 cm. 

 long, purplish, edible ; seeds 1.4 mm. long. 



39. Echinocereus enneacanthus Engelm. in Wisliz. Mem. North. Mex. 112. 

 1848. 



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



Ecliinocereus carnosus Riimpler; Forst. Handb. Cact. ed. 2. 796. 1885. 



Northern Mexico; type from San Pablo, Chihuahua. New Mexico and 

 Texas. 



Cespitose, with many stems, often forming clumps one meter in diameter or 

 more; joints often elongate, prostrate, 5 to 7 cm. in diameter; ribs 7 or 8, 

 prominent, more or less tuberculate, somewhat flabby, dull green; areoles 2.5 

 cm. apart; radial spines unequal, usually less than 12 mm. long, acicular, at 

 first yellowish, becoming brownish; central spine solitary, usually elongate. 



