NATIVE PRICKLY PEA.R IN SOUTHERN TEXAS. 5 



and number of the spines being left entirely out of consideration. 

 The two species are very similar in stature and general habit, forming 

 a hemispherical shrub about 4 feet high when fully grown. Since 

 their selection and planting, they have been described — one as 

 Opuntia gommei and the other as Opuntia cyanella. 



Opuntia gommei is a bright, more or less glossy, yellowish green 

 species with yellow flowers. 



Opuntia cyanella, on the other hand, is glaucous or waxy blue- 

 green, with flowers opening deep red but soon changing to purplish. 



Both species have yellow spines and spicules in large numbers; in 

 fact, all the native species of the delta region are among the most 

 spiny of any of the economic species of this genus of plants, their 

 spines and spicules being not only numerous, but large and stout. 

 The spines are so large and stout and die and become inflammable so 

 tardily that these delta species are among the most difficult in the 

 genus to prepare properly as food for stock. 



The first two rows previously discussed were planted to a mixture 

 of these two species in about equal quantities. 



Besides these two, a third species, which has not been botanically 

 named, having a tall habit of growth and differing in several par- 

 ticulars from the others, was planted in another row, largely for 

 comparison and to verify the writer's judgment of the species most 

 profitable to grow. In other words, it was desirable to determine 

 whether one with a little experience can go into a prickly-pear region 

 which is little known and by ordinary observation unerringly select 

 the species of most economic worth. 



At the same time that the plantings of these native species were 

 made a single row of approximately the same length as the others 

 was set in the same way to an introduced species frequently culti- 

 vated by the Mexicans about Brownsville. It is the same as one of 

 the Mission varieties so commonly grown in southern California. It 

 is the spiny "tuna blanca" of the region of San Luis Potosi, Mexico, 

 and the "tuna teca," or "tuna blanca teca," of the eastern Jalisco 

 and Aguascalientes regions. 



The third row of the field was planted to this third species (the 

 unnamed one) and it was harvested a week before row 2. The row 

 was 463 feet long and the yield, when harvested precisely as the 

 other, was 13,190 pounds, or at the rate of 77.03 tons to the acre for 

 two seasons' growth. This means an average annual growth of 

 38.51 tons per acre, as contrasted with 50.36 tons in the case of a 

 mixture of Opuntia gommei and Opuntia cyanella. 



The introduced Mission pear yielded at the rate of 42.75 tons per 

 acre per annum, which was greatly in excess of our expectations. 



