1 1 84 The Trees of Great Britain and Ireland 



2 in. wide, and often persist for many years. Branchlets of the third year purplish 

 brown, terete, smooth, and often covered with a glaucous bloom. Branchlet 

 systems irregularly disposed at varying angles, bi-pinnate, with the pinnae not in 

 one plane. Ultimate branchlets tetragonal, equal-sided, -fa in. in diameter. Leaves 

 light green or conspicuously glaucous, uniform in four ranks, appressed, marked 

 with a glandular pit on the back exuding resin, ovate-acuminate and ^ in. long on 

 young trees, ovate-acute and ^ in. long on old trees. 



Cones, on short stout straight stalks, globose, in. to f in. in diameter, 

 covered with a thick whitish bloom, ripening in the second year ; scales usually six, 

 occasionally eight, with spreading or incurved prominent processes. Seeds, eight 

 to ten on each scale, -J in. long, marked with a few inconspicuous resin-vesicles ; wings 

 narrow. 



This species is probably a northern form ' of C. lusitanica, but is distinguishable 

 by the peculiar pits on the leaves, which exude a whitish resin. The foliage, closely 

 appressed to the stout quadrangular branchlets, often glaucous in colour, and 

 covered with a protecting layer of resin, is adapted, through diminution of evapora- 

 tion, for arid sunny regions. C. arizonica is a native of the mountains of central, 

 eastern, and southern Arizona, and also occurs in the provinces of Sonora and 

 Chihuahua in northern Mexico. It was discovered in 1880 by Greene near Clifton 

 in eastern Arizona, and shortly afterwards was seen by Rusby in the San Francisco 

 mountains of the same state, where it is abundant in the canons and on northern 

 slopes, forming almost pure forests of considerable extent 2 at 5000 to 6000 ft. 

 altitude. Like most species of cypress it is variable in habit, tall and narrow, or 

 short with wide-spreading branches, and showing all tints of foliage from light 

 green to silvery white. Purpus, who gives a picture of the tree 8 in the Mogollones 

 mountains, says that it grows there on rocky places on the cliffs on the sandstone 

 formation. 



C. arizonica, introduced 4 into England in 1882 from the Arnold Arboretum, 

 U.S.A., has proved considerably hardier than its near relative C. lusitanica, and 

 promises to be a most valuable ornamental tree. At Cambridge it is one of the 

 few cypresses that thrive out of doors, and is fast in growth. The finest specimen 

 we know is growing in Messrs. Hillier's nursery at Shroner, Winchester, and is now 

 about 25 ft. high ; it bears occasionally a few cones, and is said to have been planted 

 in 1889. Another at Nymans, Handcross, was planted in 1899 when about 3 ft. 

 high, and is now 20 ft. high by 1 ft. 3 in. in girth, and is bearing cones which show in 

 the mature state none of the thick white glaucous bloom so characteristic of the fruit in 

 Arizona. None of the plants that I have seen in England show any glaucous hue 

 on the branchlets. Another tree, similar in size at the same place, procured in the 

 south of France, with bluish glaucous foliage, has not yet borne cones. A plant at 

 Castlewellan, 9 ft. high, bore fruit in 1909. At Trebah, Cornwall, a tree, obtained 

 from Messrs. Veitch about 1892, is 15 ft. high, but has not as yet produced cones. 



1 Scarcely distinguishable in botanical characters from C. lusitanica, var. giauca. 



2 In Garden and Forest, viii. 22 (1895), mention is made of a large grove, containing many thousands of trees, at the 

 Natural Bridge in central Arizona. 



3 In Mitt. deut. dendr. Ges. 1904, p. 50. * Gard. Chrm. x. 364 (1891). 



