8 BULLETIN 31, U. S. DEPARTMENT OF AGRICULTURE. 



this region make a very rapid development when transferred to 

 either San Antonio or Brownsville, Tex., and do equally well, but 

 are not so rapid in growth, at Chico, Cal. They make even better 

 vegetative growth at Brownsville than at either of the other places. 



Another region which has furnished species for the investigations 

 of the Bureau of Plant Industry produced equally surprising re- 

 sults. As a general thing species from the immediate coast of Cali- 

 fornia have not proved hardy at San Antonio, but grow very well 

 when they get slight winter protection. The inland species of Cali- 

 fornia, on the contrary, from the Pomona, Eedlands, and Banning 

 regions, are hardy at San Antonio and grow very rapidly, producing 

 much larger joints and a generally more vigorous growth. The west- 

 era species (Opuntia occidentalis) is especially worthy of mention 

 in this connection. These inland species do very poorly at Browns- 

 ville. They live, but the moisture supply is too great and they, in 

 common parlance, " get too fat " and finally break down of their own 

 weight. The large " mansa " forms so extensively grown in both 

 wild and cultivated conditions upon the central highland of Mexico 

 are generally hardy at two of the stations, Chico and Brownsville, 

 but are not hardy at San Antonio. At both Chico and Brownsville, 

 however, many of them are injured in severe seasons. All species 

 of Opuntia from the central highland of Mexico as far south as to 

 include the Federal District, are perfectly or nearly hardy at these 

 two stations. Although many species from much farther south 

 thrive well, they are usually not hardy, while species from as far south 

 as the region of Torreon are hardy at San Antonio. Several species 1 

 from the southern part of the State of Puebla and even far into 

 Oaxaca appear to be hardy at Chico, but the test with them has not 

 been of very long duration. The most tender varieties are those of 

 the Guadalajara and Guerrero region and the genus Nopalea in 

 general, none of which are able to thrive without winter protection 

 at any of the stations. They, however, thrive without heat under 

 glass shelters at Chico. 



The northern, low, hardy forms do not thrive at any of the sta- 

 tions and less so in winter than in summer, strange as it may seem. 

 They act in much the same way as the species from the drier regions. 

 They seem to become gorged with water and start to rot at the least 

 provocation. On the other hand, when kept dry during the winter 

 rainy season, they do very well at Chico. At San Antonio and 

 Brownsville they have failed to grow. 



In general, it can be said that southern Texas is adapted to the 

 vegetative development of these plants, while the Chico region of 

 California is adapted especially to the development of fruit. It is 



1 Opuntia pilifera and 0. hyptiacantha. 



