MACLOSKIE CACTACEyE. 595 



5. OPUNTIA SULFUREA Gill. 



Joints erect, subglobose, bright green. Cushions crowded. Spines of 2 

 forms, from a pallid tomentum ; the upper setaceous, black-purple, minute, 

 the lower 6-12, long, acicular, white, with purplish apex; the central one 

 longest. 



(Central provinces of Chili); N. Patagon., common by Rio Negro. 



(Spegazzini refers to 2 other undescribed species, one by Rio Sta. 

 Cruz, the other by Lago Argentine.) 



5. MAIHUENIA Phil. 



Low, almost shrubs, of habit of Opuntia, branched, forming large 

 masses, with arrow-shaped, caducous or subpersisting leaves, and areoles 

 having wool, but no glochidia. Spines sagittate, round. Flowers short- 

 stalked, from a subterminal areole; regular, not large. Ovary pitted, 

 leafy, and woolly, the wool from the axils of the leaves. Ovules 

 numerous. Perianth radiate, without a tube ; stamens shorter ; and style 

 still shorter. Berry soft. Seeds nearly lens-shaped, shining, black. 



Species 6, Chili and Argentina. Allied to Pereskia by its seeds and 

 absence of glochidia ; to Opuntia by its habit. 



1. M. PHILIPPI Web. 



Root thick, sending from its crown many branches which make a pul- 

 viniform mass, 10-20 cm. diam. Branchlets green, subglobose. Older 

 areoles foveoliform, emitting 3 spines, a central flat spine 10-15 mm - 

 long and smaller laterals, all white, paler apically. Leaves numerous at 

 end of branches, subpersistent, cylindraceous, green. Flowers sessile on 

 the extremity of the branch, 30 mm. long, green to white-rose, with scales 

 and often setulae upwards ; inner petals white. 



N. Patagon., in mountains at Neuquen ; native name Espina blanca. 



2. M. POEPPIGII Web. 



Shrub-like ; profusely branching, prostrate, forming cespitose masses, 

 pale green. Spines solitary, subulate, about 2 cm. long, yellowish. 

 Leaves cylindraceous, i cm. long, often persisting. Areoles circular, 

 1-1.5 mm - diam. Flowers sulphur-yellow. Berry subovoid, 4 by 2 cm. 



Patagon., Chubut on dry rocks near Trelew. 



