82 



THE CACTACEAE. 



51. Opuntia pulchella Engelmann, Trans. St. Louis Acad. 2: 201. 1863. 



Low, 10 to 20 cm. high, densely branched, sometimes forming compact heads 6 dm. in diameter; 

 main stem more or less definite, covered with areoles bearing yellow glochids 10 to 12 mm. long; 

 lateral joints 5 to 6 cm. long, narrowly clavate, strongly tuberculate, purplish; areoles 6 to 8 mm. 

 apart, 2 to 3 mm. broad; spines 10 to 16, slender, reddish, the longer ones 5 to 6 cm. long, somewhat 

 flattened; flower 5 cm. long, when open, fully as broad; petals purple, 3 cm. long; ovary 2 cm. long, 

 bearing numerous areoles filled with white wool and purple glochids 10 to 12 mm. long; fruit about 

 2.5 cm. long; seeds (according to Coulter) thick and round, 4 mm. in diameter, with broad flat com- 

 missure. 



Type locality: Sandy deserts on Walker River, Nevada. 



Distribution: Nevada and Arizona. 



The plant was first collected by Henry Engelmann in 1859, and brought to his brother, 

 Dr. George Engelmann. The species does not succeed well in cultivation under glass. 



Illustration: Simpson's Rep. pi. 3. 



Figure 95 is from an herbarium specimen collected by Thomas H. Means at Fallen, 

 Churchill County, Nevada, in 1909. 



FIG. 94. Opuntia parishii. Xo.66. 



FIG. 95. Opuntia pulchella Xo.66. 



52. Opuntia vilis Rose, Contr. U. S. Nat. Herb. 12: 293. 1909. 



Low, creeping, often forming mats several meters in diameter and only 10 to 15 cm. high; joints 

 prostrate, becoming erect or ascending, the ultimate vertical ones clavate, 5 cm. long, the others 2 

 to 4 cm. long, very turgid, pale green, with low tubercles; leaves terete, 2 to 3 mm. long, acute, red; 

 young areoles bearing white wool; radial spines upward of 12, the number increasing with age by 

 the addition of very small whitish ones; central spines on prostrate joints 4, reddish, white-tipped, 

 i to 4 cm. long, terete, slightly scabrous, with a sheath 5 mm. long, those of clavate joints white, 

 reddish on the upper surface at the base, and along the whole of the lower surface flattened; flowers 

 4 cm. long; petals brilliant purplish, 2 cm. long; filaments bright yellow with green bases; style 

 white; stigma-lobes yellow ; fruit pale green, blackening in drying, 2 to 2.5 cm. in diameter, 2.5 to 

 3 cm. long, tuberculate, especially about the margin of the umbilicus, spiny, fluted above, somewhat 

 dry, with large white seeds. 



Type locality: Foot-slopes and plains of Zacatecas, Mexico. 

 Distribution: State of Zacatecas, Mexico. 

 Illustrations: Contr. U. S. Nat. Herb. 12: pi. 27; f. 36. 



Figure 96 is from a photograph of the type plant taken by F. E. Lloyd in Zacatecas, 

 Mexico, in 1907. 



