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ONE HUNDRED-FIFTH PAPER 

 BLACK COTTONWOOD 



(Populous Trichocarpa — Torr. and Gr.) 



This member of the cottonwood group is a strong tree that holds 

 its ground in various latitudes and at many elevations, ranging from 

 sea level up to eight or nine thousand feet, and in latitude from 

 Alaska to southern California, a distance of nearly three thousand 

 miles. Its east and west extension is more restricted and seldom 

 exceeds four hundred miles. Its habitat covers an area of half a 

 million square miles, and in that 



space it finds conditions which vary 

 so greatly that the tree which can 

 meet them must possess remarkable 

 powers of adaptation. 



Beginning in Alaska and the inte- 

 rior of Yukon territory, it has an 

 arctic climate. It there not only 

 grows on the coast, but it strikes the 

 interior. It appears on the head- 

 waters of several streams which flow 

 into the Mackenzie or Hudson bay. 

 It passes south through British Co- 

 lumbia and enters the United States 

 west of the Eocky mountains. It has 

 been reported as far east as Idaho 

 and Montana, but further informa- 

 tion is needed before its limits in 

 that direction can be definitely fixed. 



When it enters California it pre- 

 fers the elevated valleys and can- 

 yons of the Sierra Nevadas, though 

 it occurs sparingly among the coast 

 ranges. It is generally found in the 

 Sierras at elevations of from 3,000 

 to 6,000 feet, though it occurs be- 

 tween 8,000 and 9,000. Among the 

 San Jacinto mountains of southern 

 California it grows at an altitude of 

 6,000 feet. 



When it occurs at low levels it is 

 usually found on river bottoms and 

 sand bars, in sandy and humous 

 soils, and there the largest trees 

 are found. At higher elevations it 

 is more apt to occur in canyon bot- 

 toms and gulches, in moist, sandy or 

 gravelly soil, and in such situations 

 the black cottonwood is smaller. 

 The best growth occurs where the 

 climate is humid and tlie precipita- 

 tion is great. Beyond the reach of 

 sea fogs, where the tree depends on 

 soil moisture chiefly, it is smaller. 



It is an intolerant tree. It must 

 have light. When it is crowded a 

 tall, slender trunk is developed and 

 the small crown is lifted clear above 

 its competitors into the full light. 

 If it cannot succeed in gaining that position its growth is stunted or 

 the tree meets an early death. 



The black cottonwood is the greatest of the cottonwoods. This 

 country produces no other to match it, and, as far as known, the 

 whole world has none. The Pacific coast is remarkable for the giant 

 trees it produces, but most of them are softwoods — the redwoods, the 

 big tree, the sugar pine, Douglas fir, western larch, noble fir, Sitka 

 spruce and western red cedar. Tlis cottonwood is the largest of the 

 Pacific coast hardwoods. In trunk diameter it is excelled bv the 



FdREST GROWTH BI..\CK fOTTOXWOOD 

 \V.\SHI.\GTON 



weeping oak in the interior valleys of California, but when both 

 height and diameter are considered, the black cottonwood is in the 

 West what yellow poplar is in the East, the largest of the hardwoods. 

 Sargent says this tree reaches a height of two hundred feet and a 

 diameter of eight, but Sudworth is more conservative and places the 

 trunk limit at six feet. The average size is much below the figures 



given, but abundance of logs ex- 

 ceeding three feet in diameter reach 

 the sawmills of Washington and 

 Oregon. 



Old trees range from 150 to 200 

 years in age, but trees under 100 

 years old are large enough for saw 

 timber. Records of the ages of the 

 largest trunks have not been re- 

 ported. 



Black cottonwood is a prolific 

 seeder, but the seeds do not long 

 retain their vitality. If they find 

 lodgment in damp situations, where 

 other conditions are favorable, the 

 rate of germination is high. Seed- 

 lings are often very numerous on 

 wet bars. 



The excellent quality of the wood 

 and its suitability for many pur- 

 poses bring it much demand on the 

 Pacific coast. In the state of Wash- 

 ington more than 30,000,000 feet 

 were used by wood-using industries 

 in 1910. Smaller quantities were 

 reported in Oregon and California. 

 In strength the wood is approxi- 

 mately the same as common cotton- 

 wood, but in stiffness it much ex- 

 ceeds the eastern species. Its elas- 

 ticity rates high, and compares fa- 

 vorably with some of the valuable 

 eastern hardwoods. In weight it 

 is slightly under common cotton- 

 wood. Trees are of fine form, nearly 

 always straight, and are generally 

 free from limbs to a considerable 

 height. 



The wood is grayish white, soft, 

 tough, odorless, tasteless, long- 

 fibered, nails well, is easily glued 

 and cuts into excellent rotary veneer 

 with comparatively small expendi- 

 ture of power. It does not split 

 easily after it has undergone sea- 

 soning, and this property commends 

 it to boxmakers. It is little dis- 

 posed to shrink and swell in atmos- 

 pheric changes. The absence of odor 

 and taste gives it much of its value for box making, because foods 

 are not contaminated by contact with the wood. 



It is manufactured into veneer berry baskets and is one of the 

 most suitable woods on the Pacific coast for that purpose. Candy 

 barrel makers use it in preference to most others, and a long line of 

 woodenware articles draw much of their material from this source. 

 Many thousands of cords are cut yearly for the pulp mills, where 

 material for paper is produced. Black cottonwood and white fir are 

 tlie principal woods used for pulp on the Pacific coast. 



CHEL.VN COUNTY, 



—20- 



