MACLOSKIE CACTACE^E. 593 



(Argentina) ; N. Patagon., by Rio Negro and Rio Neuqilen. 







3. ECHINOCACTUS Lk. & Otto. 



Stems globose to cylindric, with tubercles in rows, bearing clusters of 

 spines. Flowers on the subterminal tubercles. Calyx-tube prolonged, 

 scale-crowned, its outer lobes scale-like^ and its inner lobes prolonged. 

 Petals and stamens numerous, perigynous. Ovary exserted. 



Species 200, from the W. United States to Brazil and Chili. 



i. E. ACUATUS Lk. & Otto. 



Subglobose, glaucescent, the vertex not distinct, costa 2O-acuate, not 

 laterally impressed, the spines 7, spreading recurved, hoary-brown, 8-12 

 mm. long. Sulci broad. 



E, acuatus tetracantha Lehm. 



N. Patagon., on rocky hills near Rio Negro. 



2. E. GIBBOSUS DC. 



Ovate or oblong-obtuse ; costce vertical, interrupted, tubercled ; some of 

 the tubercles apically subtomentose, bearing straight, rigid needle-spines, 

 others in a different series long-mammose and subcompressed. Flowers 

 2, the largest of the genus, near the depressed apex, with greenish-tube, 

 distant sepals, having a white, expanded limb, 4-serial lobes obovate, sub- 



mucronate. 



* 



(Jamaica) ; N. Patagon., by Rio Negro. 



E. GIBBOSUS CEREBRIFORMIS. 



A monstrosity ; the ribs greatly contorted, and the spines short. 

 N. Patagon., by Rio Negro. 



E. GIBBOSUS CHUBUTENSIS Speg. 



Differs frbm the species by the statiire being low, the color intensely 

 ashy-glaucous, the spines less numerous, and \h& flowers manifestly larger. 

 Chubut, in plains along Rio Chubut. 



4- OPUNTIA Haw. Prickly Pear. 



Plants jointed, their joints flattened or cylindric, with small, subulate, 

 deciduous leaves. Cushions spine-bearing. Calyx-tube not prolonged. 



