22 AGRICULTUEAL AND MECHANICAL COLLEGE OF TEXAS. 



tend to limit the choice of species. On the northwestern plains cold 

 winters are encountered, and the number of trees adapted to the region 

 is still further reduced as they must resist all other unfavorable con- 

 ditions and also be frost hardy. Nevertheless, where soils are cultivated 

 and the trees watered during early life a wide range of species is avail- 

 able for planting throughout the Panhandle country. In South Texas 

 the selection tends toward thin foliaged types of semi-tropical trees. 

 Palms and trees of the bean family are prominent, although species 

 from all sections thrive when given proper care. 



STREET AND YARD TREES. 



In this type of planting local climatic conditions are not so impor- 

 tant as in windbreak or woodlot planting since the trees may be and 

 generally are given better care. The main factors governing the choice 

 of species are length of life, rate of growth, strength of the wood, 

 resistance to insect attacks and disease and the ultimate form of the 

 tree. It is probably true tftat a larger variety of trees can be found 

 growing along the streets and in the home grounds in Texas as a whole 

 than in almost any other State in the country. This is because Texas 

 is the natural meeting ground for species from the northern and east- 

 ern States and from Mexico. One has only to examine local tree plant- 

 ing anywhere, except in western Texas, to find a surprisingly large 

 number of species in a thrifty condition. 



In the Panhandle counties black locust represents at least 90 per 

 cent of the species planted. In spite of this fact many other species 

 grow well and should be more generally considered. Among those 

 which have been examined and which should be more extensively planted 

 are Eussian wild olive, silver maple, box elder, western cottonwood, 

 green ash, silver poplar, thornless honey locust, Japanese privet, Amer- 

 ican elm. osage orange (Bois d'Arc), salt cedar, Oriental arbor vitae, 

 Texas umbrella, red cedar and the willows and mulberries. Lombardy 

 poplar is much planted but is apt to become unsightly after a period 

 of years. Catalpa does not make a good tree on the high plains. A 

 few specimens of hackberry are found but they lack the vigor and 

 beauty of these trees as grown east of the breaks in the plains. The 

 pecan seems to grow extremely slowly but should be more carefully tested 

 out. Several of the pines, such as western yellow, Corsican, Scotch 

 and others are grown, and they are worthy of consideration for yard 

 purposes. This is also true of a number of cedars and several varieties 

 of cypress. Cedrus deodora gives promise of being a splendid orna- 

 mental tree. There are many others which it is hoped will be tried 

 out m the near future. 



In southwestern Texas, where rainfall is entirely inadequate for good 

 tree growth and where alkaline soils must be considered, black locust, 

 western cottonwood and salt cedar appear to thrive. In Pecos even 

 the business streets are lined with salt cedars, and the appearance is 

 most attractive. This tree has actually escaped to waste areas where 

 it is growing in thickets. Of the two varieties of salt cedar the plumosa 



