MACNAB CYPRESS (_Cupressus macnabiana_) is a California tree of limited range and little commercial value. It grows in Napa, Lake, Mendocino, and Trinity counties; is often little more than a branching shrub, but the largest specimens may be thirty feet high and fifteen inches in diameter. The wood is light, soft, and usually of slow growth. The medullary rays are numerous but thin, and the bands of summerwood are distinct. The cones are generally less than one inch long, and the seeds have narrow wings. The foliage is grayish which is due to white glands in the leaves. Forest foliage is fragrant. The tree is known as white cedar, Shasta cypress, and California mountain cypress.
This tree’s color is responsible for its name. It is sometimes spoken of as coast redwood to distinguish it from bigtree which grows in the interior of California. In European markets it is known as California redwood to distinguish it from other redwoods growing in distant parts of the world. Its botanical name, _Sequoia sempervirens_, means evergreen sequoia. The other species of sequoia is also evergreen. In reality, the coast redwood is less of an evergreen than the bigtree is, because the leaves of redwood turn brown two years before they fall, but there are always plenty of green leaves on the branches. The leaves are from one-quarter to one-half inch in length.
The geographical range of redwood covers about 6,000 square miles, but the commercial range is scarcely one-fifth as much. The redwood belt extends 500 miles along the Pacific coast from southern Oregon to central California. It varies from ten to thirty miles in width. It is strictly a fog belt tree, and grows poorly outside the region of ocean fog, which seldom reaches an altitude more than 2,800 feet above sea level. Where fog is thick and frequent, and soil is moist and otherwise suitable, redwood forests have grown in such luxuriance that no species in this country exceeds it. Stands running much over 100,000 feet per acre are frequent, and it is said 1,000,000 feet have been cut from a single acre.
Redwood cones are one inch or less in length. They ripen in one season. Seeds are quite small, and are equipped with wings. The bark is thick, but is much thinner than the bark of bigtrees, though it is in great ridges like the bark of that species. The habits of the two species, as to form of crown, are similar. Young redwoods, particularly if they grow in the open, develop symmetrical and conical crowns which they retain until the trunks are a foot or more in diameter. Lower limbs die and fall off after that, and old trees have crowns so small that it would seem impossible that they could supply the wood-building material for trunks so large. That the growth should be slow under such circumstances is to be expected. The ages of mature trees vary from 500 to 800 years, but an extreme age of 1,373 years is on record. The average is, therefore, considerably below that of bigtrees.