FOREST TREES OF THE PACIFIC SLOPE. 165 



reDt destructive fires have killed older trees. The early diameter growth 

 appears to be rather rapid in protected situations, where trees from 6 to 10 

 inches in diameter are from 18 to about 35 years old. Probably it would be 

 fairly long-lived, if protected from fire. 



RANGE. 



California coast barrens of Mendocino County from Ten-Mile Run southward to Na- 

 varro River, extending from aboul three-fourths of a mile of the sea inland for .". or 4 

 miles. 



OCCURRENCE. 



In "peat swamps" in wet soil of poor, shallow sand overlying a stiff, yellow clay 

 hardpan. The soil, wet by seepage from higher levels, supports low huckleberry and 

 other shrubby plants, with some peat. In these situations its growth is stunted, but in 

 better soil of borders of the barrens and of deep gullies in them, it reaches tree size. 



On poor barrens, forms dense thickets, interspersed with groups of swamp pine and, 

 occasionally, with lodgepole pine. Stunted growth of thickets is due partly to frequent 

 tires and partly to the unfavorable soil ; best growth is freer from fire. 



Climatic Conditions. — Climate moderately equable, with temperature rarely up to 

 112° and never below 12° F. Annual rainfall, between 20 and 50 inches, with an aver- 

 age of ahout 35 inches. Summers are hot and dry, but the other seasons are usually 

 humid. 



Tolbbancb. — Similar to Gowen cypress.; decided tolerence of shade is shown hy reten- 

 tion of branches in the dense, over-crowded stands. 



REPRODUCTION. — Prolific seeder. Seed similar in quality to Gowen cypress. Bears 

 cones when but a foot or two high. Reproduction abundant near seed trees. 



Macnab Cypress. 

 Cupressua macnaMona Murray. 



DISTINGUISHING CHARACTERISTICS. 



Macnab cypress is a very rare and little known tree, though several new sta- 

 tions for it have been recently discovered. It is a low, open-crowned, busby tree, 

 under 20 feet in height. Frequently it is only a many-stemmed, low, wide-spread 

 ing shrub. The largest trees have only a few feet of clear trunk and rarely 

 have a diameter of more than from 6 to 12 inches. Their bark is deep chocolate- 

 brown, tinged with red, and about one-fourth of an inch thick; Arm and very 

 distinctly cut by narrow seams into a network of rather regular, flat, connected 

 ridges, and diamond-shaped interspaces. The thin, smooth bark of branchlets is 

 dark-brown, or, where the scaly leaves have recently fallen and exposed it. clear 

 purple-red. The foliage is a dark grass-green, sometimes with a whitish tinge. 

 A minute blister-like gland distinctly marks the back of each leaf (fig. 64). 

 Except in the case of young shoots, the leaves on till branchlets are sharply or 

 bluntly pointed and closely pressed to the stems. On young shoots they are 

 keenly pointed and stand slightly away from the stems. This makes the 

 foliage prickly to the touch, ('ones (fig. 64, a) mature at the end of the second 

 summer, shed their light chocolate-brown, flat seeds late in autumn, and usually 

 remain attached to the tree for several or many seasons." At maturity the 

 cones are reddish chocolate-brown, with a pale ashy coating. They vary from 

 about three-fourths to nearly an inch in length. Sixteen to 18 seeds t fig. 64, 6 I 

 are borne under each perfect scale. The rather heavy, very narrowly winged 



" ('ones recently examined were found to be full of seed after adhering to the branch 

 for six years; moreover, the cone scales were green and spongy, appearing to be a sub- 

 stantial part of the living branch. 



