164 



THE CACTACHAK. 



This plant is rather common in cultivation in the Southwest and is now found in 

 most cactus collections. According to Dr. Griffiths, it is occasionally found wild near 

 San Antonio. We have seen somewhat similar plants from near Brownsville, Texas, 

 probably referable to one of the races of Opuntia lindheimeri. 



On account of the shape of the joints, this species is commonly called cow's tongue or 

 lengua de vaca. 



Illustration: Rep. Mo. Bot. Gard. 19: pi. 27, lower figure. 



Plate XXX represents a flowering joint of a plant obtained by Dr. MacDougal from 

 the collection of Professor J. W. Toumey at Tucson, Arizona, for the New York Botani- 

 cal Garden in 1902. 





176. Opuntia tapona Engelmann in Coulter, Contr. U. S. Nat. Herb. 3: 423. i8g6. 



Low, spreading plants rarely over 6 dm. high; joints glabrous, orbicular to obovate, 20 to 25 cm 

 in diameter, turgid, pale green; spines 2 to 4, yellow, one much longer, 5 to 7 cm. long, slender, 

 porrect or sometimes curved downward; glochids brownish; fruit 4 to 6 cm. long, clavate, dark 

 purple without, red within, spineless. 



Type locality: Near I^oreto, Lower California. 



Distribution: Southern part of Lower California. 



Figure 202 represents a joint of the plant collected by Dr. Rose on Pichilinque Island, 

 Lower California, in 1 9 1 1 . 



Related to O. tapona, but probably specifically distinct from it, is a plant growing 

 in the mountains of Cedros Island, Lower California; it was recorded from this island by 

 Dr. E. L. Greene as O. engelmannii, and a specimen was brought to Washington by Dr. 

 Rose in 191 1. This plant may be described 



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as follows: About 



I meter high; joints ob- 



long, large, 20 cm. long or more, smooth; 

 areoles 3 cm. apart or more, very large, filled 

 with brown wool; spines usually about 7, pale 

 yellow, slender, terete, the longest ones 3 

 cm. long; glochids yellow. (Rose No. 161 70.) 



Fig. 202. — Opuntia tapona. X0.4. 



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Fig. 203. — Opuntia littoralis 



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