596 PATAGONIAN EXPEDITIONS I BOTANY. 



3. MAIHUENIA TEHUELCHES Speg. 



Fruticose, intricately branching, dull green. Joints cylindro-elliptical 

 or subclavulate. Leaves ovate, small. Spines 3, the central erect, large 

 (20-40 mm.)., the laterals divaricate, small. Flowers subapical, sessile. 

 Ovary short turbinate-hemispherical, scaly, glabrous, scarcely setulose. 

 Outer petals yellow-white, inner white. Fruit globose to hemispherical, 

 not juicy. 



Patagon., between San Julian and Rio Deseado; along Rio Chubut; 

 Neuquen. Native name, Chupa sangra. 



4. M. VALENTINI Speg. 



Fruticose, intricately branching, dull green ; articulations none or ob- 

 scure. Leaves ovate, small. Spines 3, the central erect, very large, flat, 

 the lateral subretrorse, small. Flowers apical, sessile. Ovary short, scaly, 

 scales at the axils long white-bearded, with few setulae. Floral leaves 

 ruddy externally, inner ones white. 



Chubut, near Trelew, and by Rio Chubut. 



6. PTEROCACTUS K. Schumann. 



Cespitose, with club-shaped off-sets. C^^shions spiral, approximate, cir- 

 cular to obovate, small, with sparse wool ; glochidia in the young, fuga- 

 cious. Spines 9-12, small (i mm.), white. Flowers small, terminal. 

 Ovary gradually passing to the branch, with glochidiiferous cushions. 

 Outer perianth-leaves fleshy green ; inner petaloid, spatulate. Stamens 

 shorter than the perianth. Style with many stigmas. Capsule dry, with 

 circumscissile dehiscence. Seeds winged. 



i. P. KUNTZII K. Schumann? 



An elliptic to subglobose, radical tumor, with smooth epidermis sending 

 out terete branches ; which are apically rounded and with minute fascicles 

 of hairs. Spines 6-14; of these 1-4 in the center are shorter and stout. 

 Stamens irritable when touched. Capsule dry, circumscissile. Seeds 

 white. 



Common by Rio Negro, N. Patagon., a small plant, about a finger- 

 length, its branches 5 mm. thick. 



