Wood commercially divided into "white" and "black" cypress because of differences in age and environment. Fungus disease pits much wood, but stops with felling of trees.[105] [p180] FOOTNOTES [Footnote 103: See Trans. Am. Inst. M. E., Vol. XXIX, page 157.] [Footnote 104: See page 6.] [Footnote 105: Von Schrenk, Contribution No. 14, Shaw School Botany, St. Louis; also U. S. Forestry Circular No. 19.] REDWOOD. (_Sequoia_.) These trees grow only in California. There are two species: the common redwood (_S. sempervirens_), noted for its lumber, and the big or mammoth tree (_S. washingtoniana_), so remarkable for its great size. Geological evidence indicates that the genus was once represented by many species on both hemispheres, but that all disappeared during the glacial period save the two here noted. The common redwood is a large and perfect tree and supplies a wood suggesting good red cedar. This soft, light, clean, reddish-brown, durable wood works and stands well, is not easily inflamed, and is obtainable in large-sized pieces for use in large constructions. Coffins and shingles are made of it, also large quantities of wooden water-pipe employed for irrigation purposes. The average wood is seen in cheaper forms of indoor finish, while occasional pieces, in which the grain is distorted, are classed as curly redwood and used for costlier decorations. Big or Mammoth trees have been measured up to three hundred and twenty feet in height and thirty-five feet in diameter (Sargent). They are thus the largest of American trees and the most massive, although not the tallest, of all trees. Specimens twenty-five feet in diameter have been estimated as thirty-six hundred years old, and it is thought that under favorable conditions trees can survive for five thousand years, or even longer. The oldest trees are sound throughout. The almost incombustible bark is nearly two feet in thickness; the wood is brittle, but otherwise resembles ordinary redwood. It should be noted that large exceptional trees are all known, and that most of them have names such as the "Pride of the Forest," the "Grizzly Giant," and the "U. S. Grant." These, with younger trees, are grouped in [p181] the Mariposa, Calavaras, and other groves. Many sawmills are unfortunately engaged on the trees of this species. [Illustration: PLATE 35. REDWOOD (_Sequoia_). Redwood Foliage (_Sequoia sempervirens_). Giant Redwood Tree (_S. washingtoniana_). (_Courtesy Doubleday, Page & Co._) "Curly" Redwood Wood (dissection).] Redwood trees may be known by their size, locality, and fine, dull, evergreen foliage. The name Sequoia is that of an Indian chief. [p182] FOOTNOTE References: "The Big Trees of California," U. S. Forestry Division Bulletin No. 28. Also Mr. Jas. Horsburgh, Jr., Southern Pacific Railway. REDWOOD. _Sequoia sempervirens Endl._ Nomenclature. (Sudworth.) Redwood (local and common name). Sequoia, California Redwood, Coast Redwood (local).