460 Thirty-first Annual Report 



Coachilla Valley, California, to study plant introduction work 

 there. 



The Evergreen Tamarisk (7\imarix articxilaia) . In the spring of 

 1909, this department introduced the evergreen tamarisk from 

 Algiers. Along with cuttings of other tamarisks with which the 

 writer was experimenting, Dr. Trabut included six small cuttings 

 of the evergreen tamarisk. These were planted in the introduction 

 garden on the University grounds and in four years' time made a 

 growth of from 20 to 25 feet. During the cold winter of 1912-1913, 

 with a minimum temperature of 6 degrees Fahrenheit, these trees 

 were frozen nearly to the ground. They had been over-irrigated 

 and the wood was in an immature, sappy condition. Other trees 

 growing in the vicinity of the University with the wood well 

 matured, were not injured in the least by this freeze. 



On account of its symmetry and rapid growth, the evergreen 

 tamarisk became almost immediately a favorite, and it has been 

 impossible to supply the demand for cuttings. At this time it is 

 being planted extensively in parts of southern California, southern 

 Arizona, and Texas. It is regarded as one of the most rapid- 

 growing trees in the Southwest. It grows readily from cuttings 

 which, curiously enough,, may be made and planted at almost any 

 season, though rooted trees, unless kept moist, do not transplant 

 well. It is not uncommon for plants to make a growth of si.-c 

 feet from cuttings in one season. Small trees set in clumps on 

 the University grounds have made growths of 12 to 18 feet ui 

 two years' time, and there are numerous examples of evergreen 

 tamarisks in the Coachilla Valley, four and five years old, that are 

 40 feet or more in height. A brief description of this tree is found 

 in Timely Hint 121 of this Station. 



Arizona Cypress (Cupressus glabra). This is a smooth-barked 

 variety of the common Arizona cypress. It has made good growth 

 in the introduction garden and is very resistant to our conditions. 

 It grows quite erect, with ascending branches, and has light bluish 

 green foliage and smooth brown, or olive-green bark, which fails 

 off in flakes. Like other cypresses it grows readily from seeds. 



Cupressus Goveniana is a native of California, and has rather 

 slender branches which are more or less spreading and drooping. 

 It appears well suited to southern Arizona conditions and grows 

 30 to 50 feet tall. Small plants have made a growth of seven 1o 

 nine feet in two years and are very ornamental. 



Aleppo Pine (Finns halepcnsis) is a native of Syria and it is per- 

 haps the only pine that can endure the heat and aridity of southern 



