FOREST TREES OF THE PACIFIC SLOPE. 47 



Tolerance. — Demands large amount of light throughout life, especially in older age. 

 Stands may remain dense for from 10 to 15 years, but after that they thin out rapidly ; 

 trees above 20 feet in height require almost unbroken light. Trees in mature stands are 

 rarely closer than 30 feet, and the crowns seldom touch. In south, seedlings do 

 not endure intense light and heat, usually coming up in shade of old trees, in openings 

 near logs, bowlders, and brush, which afford slight protection ; in north they grow iu 

 unprotected openings. 



Reproduction. — Frequent and abundant seeder. Cones are locally produced every year, 

 so that there is always some seed in a forest; good seed years occur at intervals of from 

 3 to 5 years. Germination of natural sowing, about 50 per cent; of artificial planting, 

 from 00 to 80 per cent. Seed is produced by trees from 20 to 25 years old, bul generally 

 is scanty and of poor quality until trees are 50 years old. Large, thrifty trees produce 

 over 1,000 cones; average amount of seed, from 1 to 6 pounds. Seed is not carried Ear 

 in dense stands, but in open forests it is scattered from 500 to 700 feet from the tree 

 in direction of prevailing wind. A mature tree can seed about one-fourth of an acre in 

 an ordinary seed year. Squirrels and birds eat large numbers of seeds and disseminate 

 considerable numbers, but can not be depended on for regular reproduction. Much seed 

 is washed down steep slopes to stream beds and depressions, where good reproduction 

 often occurs. Well drained, fresh soils, and a moderate daily range of temperature are 

 necessary for germination. 



Jeffrey Pine. 

 Pin us jeffreyi " Oreg. Com." 



DISTINGUISHING CHARACTERISTICS. 



Jeffrey pine is scarcely less magnificent iu size than its associate the western 

 yellow pine. Some specialists consider it a variety of Pinus ponderosa, which 

 it resembles so closely in its habits and soil and climatic requirements that 

 from the forester's point of view there appears to be no practical reason for 

 distinguishing the two. Dendrologically, however, the typical form of 

 Jeffrey pine (discovered in northern California in 1850 by John Jeffreys) dif- 

 fers in many respects from western yellow pine. It is a large-bodied, straight 

 tree, with a long, narrow crown, the branches of which are much less stout 

 and angled than those of its relative. Its foliage is heavier, more dense, and 

 a distinctly dark blue-green. As a rule, the dark red-brown bark is deeply 

 furrowed, and the ridges, often narrow, are irregularly connected with one 

 another. On very old trees the bark is deeply broken into long, wide plates of a 

 bright red-brown color. The leaves (fig. 14, «), 5 to 9J inches long, occur in 

 bundles of 3 and persist for from 5 to 8 and sometimes 9 years. In conse- 

 quence, the foliage appears dense. The twigs of a year's growth are con- 

 siderably thicker than those of the western yellow pine, and distinctly purple 

 when young; they exhale, when cut or bruised, a fragrant, violet-like odor. 

 The cones (fig. 14), purple at maturity, are a light russet-brown after shedding 

 Their seeds, and are from 53 to 11 J inches long. The seeds (fig. 14, in, larger 

 than tbose of the western yellow pine, are similarly mottled. Seed leaves. 7 

 to Hi — sometimes 11. Wood, light straw color and rather wide grained; simi- 

 lar in commercial value to the western yellow pine. 



Longevity. — Long-lived, reaching an age of from 300 to 4to years. Further 

 age determinations are required. 



RANGE. 



Mountains of southern Oregon and southward to northern Lower California. 



OREGON. — Found at only two stations one about 30 miles south of Etoseburg, in 

 Douglas County, and the other near Waldo, in the Siskiyou Mountains. 



California. — Sources of Pitt River and thigh levels) on Scott Mountains (near Mount 

 Shasta), west of and on east slope Mount Eddy down to level and near Sissoii ; reported 

 In Trinity Mountains at elevations above 3,500 feel, and on Snow Mountain (Lake 

 County). East side of Sierras, in central and southern parts, between about l),U00 and 



