86 FOREST TREES OF THE PACIFIC SLOPE. 



California. — Several hundred acres on north slope of Siskiyous, at about 7,000 

 feet, on head of small south fork of Illinois River, just south of north boundary of 

 California and near Waldo, Oreg. South slope of Siskiyous (few miles south of last 

 grovei. on headwaters of small northern tributary of Klamath River, at 7,500 feet 

 elevation. About 600 acres at head of Elk Creek (tributary Klamath River) on high 

 peak 2 to 3 miles west of Marble Mountain, and 80 miles west of Mount Shasta 

 (Siskiyou County, Cal.) ; elevation, a little below 8,000 feet; several hundred trees on 

 north side near summit. Summits of Klamath Mountains ; locations not determined. 

 Trinity Mountains, crests of ridges ; noted (in T. 35 N., R. 10 W.) at head of Canyon 

 Creek from 7 miles above Dedrick (at 4,500 ft.) to lakes at over 6,000 feet, and near 

 divide between Stewart Fork of Trinity River and Canyon Creek, at 6,000 feet. Said 

 to have been found in 1S63 on Black Butte (north of Strawberry Valley) at base of 

 Mount Shasta, but not seen there since. Headwaters of Parks Creek (tributary Shasta 

 River), north slopes above 5,500 feet on north side of Shasta-Trinity Divide (T. 41 N., 

 R. 6 W.) in Shasta National Forest. This is in neighborhood of the west Shasta sta- 

 tion, and indicates that the early one may be found. Reported as abundant on north 

 and east sides of Mount Shasta, but authentic records are lacking. 



OCCURRENCE. 



Steep north mountain slopes, ridges, and about protected heads of mountain streams. 

 Dry. rocky soils, but best on deeper, moist, porous soils. Forms pure, rather open stands 

 on small areas, but is commonly associated with black hemlock, straggling Douglas fir, 

 white fir, incense cedar, western white pine, sugar pine. 



Climatic Conditions. — Temperature moderate, rarely much below zero, or above 

 100° F. Precipitation, from 20 to 60 inches, snow. Snowfall often 15 or 20 feet deep 

 and remaining on ground more than half of year. Atmosphere humid through greater 

 part of year. 



Tolerance. — Little is known of its silvical characteristics. Its dense foliage, and 

 habit of retaining low side branches in rather close stand, indicates considerable tolerance 

 of shade. 



Reproduction. — Information on its seeding habits and reproduction is lacking. It 

 appears to be a fairly good periodic seeder, intervals of good production probably not 

 less than two or three years. 



Black Spruce. 

 Picea mariana (Mill.) B.. S. & P. 



DISTINGUISHING CHARACTERISTICS. 



Black spruce is mainly au eastern and far northern species, included as a 

 Pacific tree because of its occurrence in the interior of Alaska. Here it is a 

 small or stunted tree, rarely over 12 to 15 feet high, and often only from 2 to 6 

 feet high ; elsewhere from 25 to 40 feet high and from 4 to 8 inches in diameter. 

 Exceptionally it attains a height of from 50 to 80 feet and a diameter of 1 foot. 

 The crown is characteristically open and irregular, extending to the ground 

 except in middle-aged or old trees grown in a dense stand, in which the lower 

 half of the crown branches are shaded out. The branches are short, slim, and 

 often distant from each other. In forms of this tree growing in wet marshes 

 there are tufts of short branches only, or chiefly, at the top of the stunted stem. 

 On less wet or moist ground the crown branches are more numerous. As a 

 rule, the branches droop at their ends, but sometimes they are peculiarly stiff 

 and horizontal. The foliage is a deep blue-green, with a tinge of whitish, 

 while the short leaves (fig. 32) stand out on the branches. Bark of older trees 

 is thin and composed of small ashy-brown scales. The young twigs of a season's 

 growth are usually a pale russet-brown, coated with small hairs of similar 

 color. The cones (fig. 32) are ripe by the end of August, and within a few 

 weeks afterward they shed their small winged seeds (fig. 32, a) : at this time 

 they are a pale ashy-brown. Their habit of remaining firmly attached to the 

 branches for very many years furnishes one of the most reliable means of dis- 



