OPUNTIA. 



135 



grows as if native; on some of these hills it is the dominant and sometimes exclusive plant. 

 In the same general region, however, one finds the plant about the houses, especially on 

 walls, where it has undoubtedly been planted. At Oruro, Bolivia, it was seen only in the 

 wild state, while at several stations along the railroad between Juliaca and Cuzco, Peru, 

 especially at Combatata and Tinta, Peru, it has been planted on top of many of the mud 

 walls about the yards. On the hills below Pampa de Arrieros, Peru, the species is extremely 

 common and undoubtedly native. 



The plant is known everywhere by the natives as ayrampo. The seeds are collected in 

 great quantity and dried, and may be bought in the market places, especially in Arequipa. 

 Indeed, there must have been a time when they were shipped by freight, for the name 

 Ayrampo has always appeared on the printed freight classification of the Southern Railroad 

 of Peru. The assistant superintendent of the road, Mr. Brown, states that, so far as he 

 knows, there are few or no shipments made now. One of the places in Peru where Dr. 

 Rose found the plant very abundant is named Ayrampal. 



The dry seeds, when placed in water, yield a red substance 

 which is used for coloring jellies and gelatine and, according to some, 

 for coloring wines. In former days the Indians also used this sub- 

 stance in some of their carnival ceremonies. The coloring matter 

 does not come from the seeds themselves, but from the red juice of 

 the fruit which has dried on the surfaces. 



Figure 169 represents a joint of this species collected by Dr. 

 Rose at Oruro, Bolivia, in 1914. 



130. Opuntia microdisca Weber, Diet. Hort. Bois 896. 1898. 



FIG. 169. Opuntia soehrensii. 

 Xo. 4 . 



Forming small clumps, very much branched, prostrate; joints mostly obovate to oblong, 4 to 

 8 cm. long, usually much flattened, but sometimes nearly cylindric, grayish green; leaves minute, 

 purple, soon dropping off; areoles numerous, 5 to 6 mm. apart, rather large, when young densely 

 white-felted; spines 10 to 15, white to reddish, unequal, some of the centrals 1.5 to 2.5 cm. long; 

 glochids numerous, yellow ; flower-buds red; flowers 2.5 cm. long, bright red; filaments purple; style 

 white; stigma-lobes 6 to 8, short; ovary turbinate, 16 mm. long, bearing numerous areoles sub- 

 tended by narrow red leaves; areoles on ovary densely felted and 

 bristly; fruit red. 



Type locality: In Catamarca, Argentina. 



Distribution: Northern Argentina. 



Schumann refers this species to Platyopuntia, while Weber 

 referred it to Tephrocactits. It evidently belongs to our Sul- 

 phurcac, being nearest our 0. soehrensii. 



Our description is drawn chiefly from specimens obtained 

 by J. A. Shafer between Andalgala and Concepcion, Argen- 

 tina, in 1916, supplemented by a living specimen obtained by 

 Dr. Spegazzini in 1915. In Argentina this species also is 

 known as ayrampo. 



Figure 170 represents a joint of the plant collected by J. A. 

 Shafer between Andalgala and Concepcion, Argentina, Decem- 

 ber 28, 1916 (No. 24). 



To this relationship may belong the following species: 



OPUNTIA PENICILLIGERA Spegazzini, Anal. Mus. Nac. Buenos Aires FI- 170. Joint of Opuntia micro- 



TT disca. Xo.7. 



II. 4: 291. 1902. 



Low, nearly prostrate; joints flattened, orbicular to broadly obovate, 10 to 12 cm. long, 7 to 

 10 cm. broad, dull green; spines slender, twisted, one elongated and i to 5 cm. long, the others much 

 shorter, all white; glochids brownish; flowers from the lateral and marginal areoles, citron-yellow; 



