MACLOSKIE CACTACE/E. 593 



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



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, costce 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 ; costcz 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 from the species by the stature being low, the color intensely 

 ashy-glaucous, the spines less numerous, and \heflowers 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. 



