12 Proceedings of the Biological Society of Washington. 



ascending at extremities ; joints broadly obovate, often as broad as longr, 

 about 20 cm. in diameter, yellowish-green with a little bloom, slightly 

 raised at areoles even at second year; areoles dark, broadly obovate, 5 

 to 6 mm. in length; spicules yellow, 2 to 3 mm. long on sides of joints 

 and compact along upper edge of areole, but on edges of joints they are 

 divergent, prominent, 8 to 12 mm. long; spines formidable, divergent, 

 stout, flattened, twisted, having light reddish-brown bases and gradually 

 fading distally to white, 3 to 4, large, 3 to 4 cm. long, and 1 or 2 short 

 white ones below, 1 to 1}^ cm. long; flower deep yellow, red within, 

 turning deeper yellow and red centre enlarging as day advances, 7^ cm. 

 in diameter when fully opened, resembling that of 0. phaeacantha 

 brunnea, but larger throughout, filaments light-greenish below, style 

 white, stigma large, very light green, 12-parted, with narrow segments; 

 fruit light red with a tinge of purple and a little bloom toward maturity, 

 but almost none when fully ripe, obovate to elliptical, about 4x5 cm. 

 with a sunken, large, roughened scar, rind greenish and pulp colorless, 

 areoles tawney, 2 mm. in diameter, spicules yellow, 2 mm. long, unequal, 

 fugacious spines yellow but lighter and often white distally, 5 to 12 mm. 

 long. 



The species belongs to the phaeacantha group and differs from any of 

 the described forms in that group in being larger throughout, and in 

 having a different spination. The color of the spines resembles most 

 closely that of phaeacantha brunnea of the second year's growth, but is 

 even lighter colored than that. It is found rather commonly in the foot- 

 hills of the Rellito and Santa Cruz Valleys of Arizona. The type specimen 

 was collected near Pantano, Arizona, in September, 1911, under my 

 collection number 10,452. 



Opuntia recurvospina sp. nov. 



An erect, open-branched species, 1 m. or more high and 1)4 to 2 m. in 

 spread of branch; joints obovate, contracted below into a stipitate base, 

 but often widest at middle, commonly narrowed above into a sharply 

 rounded apex, mostly about 18 by 32 cm., having a little bloom on last 

 year's growth but current season's joints a clear, slightly yellowish-green 

 and decidedly yellowish-green in age; areoles subcircular to broadly oval, 

 brown with compactly formed wool, 1 to 1)4 mm. high, 5 to 6 mm. long, 

 enlarging slightly in age; spicules comparitively few, yellow, scattered 

 through upper edges of areoles, unequal, 4 mm. or less in length in an 

 occasional areole only, increasing but slightly with age; spines white with 

 light brown to flesh-colored bases, flattened, twisted, 2 to 5 in number, 

 mostly 2 or 3, spreading in all directions the second year and after that 

 tightly recurved in all directions; flowers light yellow, 8 cm. in diameter, 

 slightly greenish tinged within, filaments light above, greenish below, 

 style white, stigma light-green, globose, 10-parted; fruit obovate, pyriform, 

 about 4 by 7 cm., deeply pitted, purplish-red throughout, having a little 

 bloom up to maturity but after that deep dark-red, its areoles tawney, 

 with prominent wool, spicules yellow, 4 mm. long, unequal, located in 

 central upper portion of areole, fugacious spines, remarkably prominent, 



