TUNA AND ITS DISTRIBUTION. 167 



grows spontaneously and abundantly not only over a great geograph- 

 ical area, but within a great vertical range above the level of the sea. 

 I have seen it growing thriftily, but of comparatively small size, at not 

 less than 5,000 feet above that level, but the most vigorous plants were 

 found in the fertile valleys of slight elevation. In such positions 

 plants not unfrequently reach a height of ten or twelve feet, and a 

 diameter at the base of the stem of six or seven inches. 



Compared with its abundant growth, little economic use is made 

 of tuna. Its fig-like fruit is sometimes eaten, but it can hardly be said 

 to be palatable human food, and, like other cactus fruits, it is decidedly 

 laxative. If it were not for its armature of spines it would be more or 

 less valuable as a forage plant, especially as it is always succulent, 

 even during the dryest seasons. Still the "fronds" are sometimes 

 soused in a small way after removing the spines. I once saw a ranch- 

 man preparing them by impaling them upon a pitchfork and holding 

 them for a few seconds over a blazing brush fire. The spines, being 

 dry, were quickly burned off, while the succulent "fronds" were 

 hardly scorched. They were thrown immediately to the cattle, who 

 ate them greedily and easil5^ 



With the probable exception of the partial use of tiii~ia in Central 

 America as a habitat for the cochineal insect, its most important use 

 seems to have been as a hedge plant. It is hardly comparable with 

 the hedge plants of other countries, but it is apparently the best one 

 in its native regions. The traveler not unfrequently sees the tuna, as 

 well as other Opuntias, used by the natives to form their garden in- 

 closures, and the early Jesuit missionaries often made effective hedges 

 of it about their mission grounds. Portions of some of these ancient 

 hedges are still growing, although the buildings they originally in- 

 closed are in ruins. The vigorous growth of the plants has insured 

 the perpetuity of those hedges, but it is evidently their armature of 

 spines, rather than their resistant strength, that made them an effect- 

 ive barrier against both animal and human intruders, and that origin- 

 ally suggested their use for hedges. 



In Southern Europe and the Orient Opiintia tuna grows with such 

 wild spontaneity that only the historical fact informs the traveler that 

 it is an acclimated American stranger. Indeed, by a large proportion 

 of travelers and residents in those countries it is believed to be a 

 native member of their flora. I found it growing with as great vigor 

 at Jaffa and elsewhere on the Plain of Sharon, and at Jericho, on the 

 Plain of the Jordan, as I had ever seen it in America. The former 

 plain is only a little above sea level, but the latter is fully 1,200 feet 

 below that level. I have thus personally observed this plant to have 

 a vertical range of more than 6,000 feet, and a geographical range 



