8 THE MISTLETOE PEST IN THE SOUTHWEST. 



Oregon and Washington. Eastward its northern limit is in New 

 Jersey, southern Pennsylvania, southern Ohio, Indiana, Illinois, 

 Missouri, and eastern Oklahoma. Speaking generally, mistletoe is 

 held in rather high regard everywhere because of its inherently 

 interesting mode of life, because of the traditional and historical 

 atmosphere which invests the original mistletoe of Europe, and 

 because of its desirability, for the above and other reasons, as a 

 decorative Christmas shrub. The fact that it is a parasite implies a 

 possible injury to the tree upon which it grows, but, again speaking 

 generally, the injury is regarded as relatively slight and more than 

 offset by the feeling of regard for the parasite. Among people who 

 see it rarely, and, especially among those living in northern cities 

 who purchase small sprigs or bunches of it at a good price for 

 Christmas decoration, the idea of mistletoe being a harmful parasite 

 upon trees is quite lost sight of. Nevertheless, there are localities in 

 which mistletoe becomes so abundant upon trees and so harmful to 

 them as to make the control of it or its extermination a serious 

 practical question. 



This is notably the case in parts of Texas. Between the ninety- 

 sixth and ninety-seventh meridians in Texas is a belt of country in 

 which mistletoe is a serious parasite in many localities. The area 

 most harmfully infected would be comprised in a circle of 100 miles, 

 more or less, in radius, having its center at Austin. The north- 

 south extension of this area is really greater than its east-west dimen- 

 sions, for to the eastward one passes presently into the more humid 

 and more heavily timbered country, and westward the available 

 hosts for the parasite become fewer. 



The climatic conditions of this area have a more or less direct 

 bearing upon the question. Between the ninety-sixth and ninety- 

 seventh meridians in Texas and Oklahoma lies a zone of transition 

 from the humid climate of the Gulf States to the arid climate of the 

 Southwest. The heavy forest growth of the South does not enter 

 this belt, except as it follows the moist soils of river and creek bottoms, 

 and even in these favorable situations the luxuriant growth becomes 

 checked by the decreasing rainfall and drier atmosphere. Upland 

 tree growth is stunted; the trees occur more sparsely, are broader of 

 crown, less tall, and more frequently of imperfect growth. The 

 trees bear evidence of a struggle against unfavorable conditions. In 

 this region it becomes a difficult matter to secure umbrageous trees 

 for shading and beautifying streets and parks and private grounds. 

 Not many native species are suitable for these purposes. Very 

 little has been done toward the solution of the whole question of 

 selection, planting, and care of shade trees. 



In spite of the less inviting conditions for forest growth, mistletoe 

 appears to flourish better in this belt than elsewhere; at least, it is 



