CYPRESS AND JUNIPER TREES OF ROCKY MOUNTAIN REGION. 9 



Mr. Alfred Rchder detected i Cupressus glabra in Oak Creek Canyon, 

 about 20 miles south of Flagstaff, Ariz. In the same year Mr. R. D. 

 Forbes found this species at various points in the Tonto National 

 Forest, Arizona. Further search is likely to reveal its existence 

 elsewhere in Arizona and possibly also in New Mexico and Mexico. 



The name "smooth cypress" is adopted here as descriptive of the 

 tree's most conspicuous characteristic, its smooth, purple-red bark 

 Settlers in the Verde River Canyon knew this tree long before its 

 technical discovery and called it "yew-wood," doubtless because 

 the bark of the trunk resembles that of the western yew (Taxus 

 hrerifolia) . 



DISTINGUISHING CHARACTERISTICS. 



In general appearance the foliage of smooth cypress resembles 

 that of the Arizona cypress, though the former species can be dis- 

 tinguished from the latter by the compact, narrowly oval, or some- 

 what pyramidal crown. The branches of smooth cypress, particularly 

 of younger trees, are strongly upright. Old trees grown in the open 

 develop long, lower branches, which from their great weight are less 

 upright than those of trees of the same age in a close stand. In 

 height the trees range from 25 to 30 feet, and in diameter from 10 to 

 14 inches, though much larger trees probably exist. 2 The trunk is 

 slightly tapering, while the upper portion is sometimes divided into 

 several branches, in this respect differing from the usual undivided 

 stem of Arizona cypress. Only about one-fourth to one- third of 

 the trunk is clear of branches (PI. Ill, left). 



The most distinctive characteristic of this tree is its thin, smooth, 

 dark purple-red bark. Each season's growth of bark, from one- 

 sixteenth to one-eighth of an inch thick, breaks irregularly into 

 small, curled, scalelike plates, which fall away during the succeeding 

 autumn and winter, leaving the trunk smooth. Vigorous trees shed 

 their bark more rapidly and completely than less thrifty ones. The 

 jliage is a bright blue-green (glaucous). The minute, scalelike, 

 acutely pointed leaves (PI. IV), about one-sixteenth of an inch long 

 and closely pressed on old sprays, are thickened and keeled on the 

 back, where in practically every case there is a comparatively large 

 resin gland, a characteristic which distinguishes the leaves from those 

 of Arizona cypress. Young shoots bear closely pressed leaves from 

 one-fourth to one-half of an inch long, with very keen and more or 

 less spreading points (PI. V, a). The leaves die during the second 

 year, turn a bright red-brown, and remain on the twigs for about 4 

 years, after which they are shed slowly, and later these small branches 



i Reported to the writer in letter by Prof. C S. Sargent, Nov. 6, 1914. 



2 According to Prof. J. W. Tourney (loc. cit.) some of the trees in the "Natural Bridge" grove (which 

 must now be considered to be C glabra) are 3 feet in diameter. 



