8 BULLETIN 207, U. S. DEPARTMENT OF AGRICULTURE. 



trees they may retain their vitality for at least several years. 1 Re- 

 production takes place abundantly where the exposed mineral soil is 

 moist and not subject to washing by mountain floods. Seedlings 

 are scarce, therefore, on steep, rocky slopes, only appearing where 

 the seed has lodged in pockets and crevices. A small amount of the 

 seed is eaten by rodents. 



LONGEVITY. 



The exact age attained by Arizona cypress is not at present known, 

 but, judging from the few records available, it is evidently long-lived. 

 Trees from 12 to 38 inches in diameter, in full enjoyment of top 

 light, are from 100 to 310 years old, while suppressed, slow-growing 

 trees from 4^ to 5 inches in diameter may be from 50 to 65 years 

 old. The largest trees known would doubtless prove to be from 

 375 to 400 years old. 



SMOOTH CYPRESS. 



Cupressus glabra Sudworth. 



COMMON NAME AND EARLY HISTORY. 



The first reference to this new and handsome cypress was published 

 in 1895 and was based on the discovery of a grove on Pine Creek 

 at "Natural Bridge," central Arizona, by Prof. J. W. Tourney, who 

 believed the tree to be a form of Arizona cypress. 2 It was not dis- 

 tinguished from the latter tree, however, until February, 1910, when 

 it was named and described 3 from a grove of trees discovered by 

 Mr. Arthur H. Zachau on the north slope of a small tributary stream 

 on the west side of the Verde River Canyon, about 16 miles south- 

 east of the town of Camp Verde, Ariz. This grove covers an area 

 about 6 miles long by 1J miles wide. 4 In size and development the 

 trees there are fairly representative of the species. In 1910 Mr. 

 Willard Drake reported finding the species on the Coconino National 

 Forest, growing with Arizona cypress, while in the same year Mr. 

 R. L. Rogers observed it in the Coronado National Forest. Recently 



1 No systematic tests have yet been made to determine exactly how long such seeds will retain their 

 germinative vitality. In many cases, however, the author has found perfectly sound seeds in closed cones 

 that have been attached to living trees for eight or nine years. It is probable that still older seeds could 

 be found. 



2 Garden and Forest, VIII, 32, 1895. While Prof. Tourney referred to the Pine Creek trees as C. arizonica, 

 he nevertheless expressed doubt as to their being the same as the Arizona cypress of the Chiricahua Moun- 

 tains, for he observed that the bark of the Pine Creek trees "peels off in long shreds." 



Prof. Tourney's reference to this characteristic of the bark led the writer to suspect the "Natural 

 Bridge" cypress to be the same as the Verde River Canyon tree. Prof. C S. Sargent has recently 

 examined specimens of Prof. Tourney's "Natural Bridge'' tree and finds it to be C. glabra, so that this 

 grove can now be added to the tree's range. 



s American Forestry, XVI, 88, 1910. 



4 This grove is partly on a ranch belonging to William A. Tinsley, and approximately in township 11 

 north, range 5 east, where Mr. Zachau saw it first in 1907, and called the writer's attention to the fact 

 that the trees there had very different bark from that of the Arizona cypress, common in the Chiricahua 

 Mountains. Special credit is due Mr. Zachau for this most important observation, which resulted in an 

 investigation of these trees by the writer and in the discovery then that they are of a distinct species. 



