10 Proceedings of the Biological Society of Washington. 



closely Opuniia engelmannii than any other species. The type is preserved 

 under my inventory number 10,560, collected near Owens Post Office, 

 Arizona, May 3, 1912. 



Opuntia intricata sp. nov. 



Plants large, half prostrate, with long tangled arms often nearly a m. 

 in length, mostly lying in a mass, one on top of the other; joints obovate, 

 commonly 11 by 20 cm. glaucous blue-green, variable in size but outline 

 quite uniform, pruinosity lost with age; areoles obovate, 3 mm. long on 

 sides, and 4 mm. on edges of joints, with conspicuous wool, brown and 

 tawney white at margin when young, changing in age to dirty gray; 

 spicules rather bright yellow in a compact triangular tuft in upper portion 

 of areole, about 2 mm. long, increasing in age, and at 2 or 3 years filling 

 entire areole which becomes enlarged and subcircular; spines scattering, 

 only on edges of joints, at apex 1 to 3, mostly 1 to 2, basal portion light 

 yellowish brown, fading to white at about half its length, 2 to 3 cm. long, 

 flattened, twisted, not consistently but frequently annular; flowers light 

 purplish, filaments pinkish above, greenish below, style white with a tinge 

 of reddish above, stigma light green, 8-parted ; fruit obovate, pyriform, 

 light purplish-red with abundant bloom, rind and pulp tinting tardily, 

 about 4 by %% cm. 



This species is rather common in the lower parts of the mountain 

 valleys, and upon the sandy alluvial bottoms at the mouths of washes 

 above San Bernardino, California, and in similar positions southward. 

 Old, mature plants have the habits described above. When grown under 

 cultivation, however, the plants may be erect, or ascending until the arms 

 reach a length of 50 to 75 cm., when they begin to bend over in a tangled 

 mass upon the ground; or as is frequently the case in cultivation, break 

 off at the articulations. This species is found in some of the European 

 collections, and there is not much doubt but that their material was 

 secured originally from A. H. Alvord of San Bernardino, California, who 

 made extensive collections in the region. It has been referred liy Euro- 

 pean collectors as a variety of Op. basilaris but it does not belong to that 

 group. This description has been prepared from various notes made in 

 the field, and from cultivated plants grown at Chico, California. The 

 type bears my collection number 10,372 from near San Bernardino, Cali- 

 fornia, May, 1912. 



Opuntia aciculata sp. nov. 



A low hemispherical shrub, 1 m. high, and 1^ to 2 m. in spread of 

 branch, erect or main arms ascending or even resting on edge, and the 

 secondary erect from them; joints ovate to obovate, mostly pointed above 

 and below, 15 by 20 cm., but the older joints on our plants only 12 by 

 17 cm., dark green with some bloom; leaves circular in section, subulate, 

 cuspidate, 7 mm. long, gradually recurved as they age; areoles subcircu- 

 lar, varying from 4 to 6 mm. in diameter with the conspicuous brown 

 wool 1 mm. or more above the surface of the joint, about 2^ cm. apart 

 on sides of joints; spicules bright brown, conspicuous and formidable, 5 



