JULY 1 TO SEPTEMBER 30, 1915. 47 



41168 to 41243. 



From Peru. Collected by Mr. O. F. Cook, of the Bureau of Plant Industry. 

 Received September 16, 1915. Quoted notes by Mr. Cook. 



41168 to 41176. Oxalis tuberosa Molina. Oxalidacese. Oca. 



"A plant related to our common sheep sorrel, widely cultivated in Peru 

 and Bolivia for the sake of its fleshy rootstocks, which are an important 

 article of food. In some districts ocas are second only to potatoes, while 

 in others ullucus are more important, or at least are sold more generally 

 in the native markets. Ocas are eaten raw as well as cooked, and are also 

 frozen and dried. Ocas prepared in this way are called caya, a term 

 corresponding to chuno (chunyo), the name of the dried potatoes. Raw 

 ocas when first dug have a distinctly acid taste, like sheep sorrel, but 

 this is lost after the tubers have been exposed to the sun. The plant at- 

 tains a height of 1 foot or more and has the general appearance of a 

 large sheep sorrel. The flowers are yellow and the leaflets are folded at 

 night or in wet weather, the same as sheep sorrel. The varieties are 

 numerous, though much fewer than in the case of the potato. Some are 

 preferred for eating raw and others for the making of caya. The texture 

 of the tubers is very tender, crisp, and juicy. In form some are nearly 

 cylindrical, while others are slender at the base and strongly thickened 

 at the end. The colors vary from white* or light pink through darker pinks 

 or yellows to deep purplish red. The range of colors is much the same as 

 in the ullucu, but no deep-yellow varieties were seen, nor any with spots, 

 except that some have bands of deeper color across the eyes. In addi- 

 tion to the pleasing coloration, the surface of the tubers is smooth and 

 clear, so that the general appearance is very attractive. If the taste 

 should prove acceptable, ocas might become very popular for salads and 

 pickles, if not for other purposes. The nature and habits of the plant 

 indicate that it may be adapted to acid soils, which would be a distinct 

 advantage in some parts of the United States." 



Tubers. 



41168. "No. 2021. Ollantaytambo, Peru, June 16, 1915. Zapallo 

 oca. Pale yellow color of squash, with deep red bands across eyes ; 

 large specimens 8.5 cm. by 1 cm." 



41169. "No. 1223. Ollantaytambo, Peru, June 16, 1915. Higos oca." 



41170. "No. 2033. Sicuani (Ushcopata), Peru, April 9, 1915. Ten 

 tubers in one hill." 



41171. "No. 2026. Sicuani, Peru. April 4, 1915. Uanccolema. 

 White variety, scarcely pinkish at the ends. More slender than 

 the papa oca." 



41172. "No. 2030. Sicuani, Peru, April P. L915. Cachu oca. 

 Smaller and more slender than the others {papa oca. No. 2025, and 

 hanccolema, No. 2026), and eyes not so close set. Pinkish all 

 over, but much lighter than the preceding. Considered better for 

 eating raw." 



41173. "No. 2032. Sicuani (Ushcopata), Peru, April 9, L915. 

 Yuracj oca. At Ushcopata, a few miles above Sisuani. two more 

 kinds of ocas were found, a reddish variety, smaller than papa oca. 

 called pocalluchu, and a white variety, with very broad fasciated 

 stems, called yuracj oca." 



