94 



THE CACTACEAE. 



species is beyond the limits hitherto assigned to any of the order, which are not recorded as growing 

 much south of the tropic of Capricorn. The climate is remarkably dry and clear, hot in summer, 

 but with sharp frosts during the winter nights. He found Cacti both abundant and of a large size, 

 a little farther to the north at Rio-Negro in latitude 41 S. 



Illustration: Mag. Zool. Bot. i: pi. 14, f. i. 



Figure 109 is copied from a photograph of an herbarium specimen collected by Carl 

 Skottsberg in Patagonia in 1908. 



65. Opuntia tarapacana Philippi, Anal. Mus. Nac. Chile i8gi 2 : 27. 1891. 

 Opuntia rahmeri Philippi, Anal. Mus. Nac. Chile iSpi 1 : 27. 1891. 



Low, cespitose plants; joints small, ovoid, about 2 cm. long by i cm. thick, bearing spines from 

 white woolly areoles at tips; spines usually 3, straight, 12 to 15 mm. long, white with yellowish tips; 

 flowers yellow; petals 21 mm. long; ovary elongated, 2 cm. long. 



Type locality: Calalaste, Chile. 



Distribution: Known only from type locality, although Schumann in his Keys refers 

 this species to Bolivia. 



Although the type of this species is preserved in the Museum at Santiago, Chile, it is 

 insufficient to enable us to give a very full description. It seems distinct from the other 

 species of the group. 



KIG. 109. O. darwinii. Xo.6. 



FIG. no. O. atacamensis. Xo.6. 



FIG. in. O. russellii. Xo 6. 



66. Opuntia atacamensis Philippi, Fl. Atac. 24. 1860. 



? Pereskia glomerata Pfeiffer, Enutn. Cact. 179. 1837. Not Opitnlia glomerata Haworth. 1830. 



Growing in large, dense clusters sometimes 6 dm. broad and 3 dm. high; joints ovoid, 2.5 cm. 

 long by 2 cm. in diameter; areoles in 5 to 7 series, the lower ones with wool and very short spines; 

 upper areoles each bearing i erect central spine 1 8 to 25 mm. long, yellow or reddish; radial spines 

 2 to 4, strongly appressed, 2 mm. long; flowers yellow. 



Type locality: Prof etas, Chile; also Puquios, 23 50' south latitude. 



Distribution: On the high central deserts of northern Chile at an altitude of 2,700 

 to 3,300 meters. 



We have not seen the type of this species, and our reference of Pereskia glomerata here 

 may not be correct. 



Illustration: Nov. Act. Soc. Set. Upsal. IV. i 1 : pi. i, as Opuntia grata. 



Figure no represents a plant obtained by Dr. Rose at the Botanical Garden, Santiago, 

 Chile, in 1914. 



67. Opuntia russellii sp. nov. 



Forming small, compact clumps i to 2 dm. in diameter; joints small, globular to obovoid, dull 

 green to more or less purplish, 2 to 4 cm. long, very spiny near the top; leaves minute, acute, soon 

 falling; prominent spines 3 to 6, yellow, 2 to 3 cm. long, slightly flattened; accessory spines i to 



