94 THE- AMERICAN BOTANIST 



tvajanl Britton & Rose, are a regular food staple and are found 

 in the markets of Tehuacan in the month of May. Griffiths 

 tells us that very palatable jellies are manufactured in Mexico 

 from the prickly pear fruits, and the young joints are made 

 into pickles. 



Forage. Probably the most important use of the cactus is, 

 or at least will soon be, its use as a forage plant in desert 

 regions. The cacti used for forage are practically confined to 

 the genus Opuntia, of which the flat-jointed kind, or prickly 

 pears, and the round-jointed, or chollas, are both useful, the 

 former for its joints, the latter for its fruits. "Cholla" is a 

 term applied to the fruit and also the entire plant of the round- 

 jointed Opuntia. The fruit is eagerly eaten by sheep, with no 

 bad effects, but it lacks sufficient nitrogen to sustain life for an 

 extended period when it forms the sole article of diet. The 

 chief drawback to the use of prickly pear joints as forage is, 

 of course, the spines, although cattle do not hesitate in an 

 emergency to devour anything which contains water. Experi- 

 ments with the singeing of cacti to remove the spines have been 

 quite successful in Arizona, according to J. J. Thornber, al- 

 though the cost of the operation is an important factor. The 

 so-called "spineless cactus" of Luther Burbank has been found 

 to revert back to the spiny condition of its ancestors, but there 

 are two or three nearly spineless Opuutias which are native in 

 New Mexico and Mexico which promise much for the future. 



However, the cactus can only be utilized as an emergency 

 ration. It is in tiding over periods of drought that it has 

 proven so valuable in the past. The cattle are able to subsist 

 with no water at all when cacti compose the greater part of 

 their diet. 



Fuel. The amount of available fuel in an arid country is 

 necessarily so small that anything which will burn is used, and 

 the dried stems and trunks of most of the cacti are very wel- 

 come to the inhabitants of the American deserts. The large 

 columnar species of course furnish excellent fuel. 



