356 FOREST TREES OF THE PACIFIC SLOPE. 



California. — Water courses and chaparral of middle elevations, south on Sierra Nevada 

 to head of Kern River, on north coast ranges to San Francisco Bay, and on south coast 

 ranges from Santa Cruz Mountains to San Jacinto Mountains, at the north at 3,500 to 

 5,500 feet and at the south at 5,000 to 9,000 feet. Noted in Mount Shasta National 

 Forest, base of Mount Shasta at 3,500 to 5,500 feet and south to the "Loop" on Sacra- 

 mento River; Wagon Camp (5,750 feet on Mount Shasta), Sissons (3,500 feet), and Upper 

 Soda Springs (Siskiyou County) ; coast ranges, rare in Humboldt County and southward. 

 Trinity and Stony Creek National Forests' highest ridges such as Canyon Creek lakes, and 

 Black Buttes, Mount Tamalpais, and Oakland Hills around San Francisco Bay ; Sierra 

 Nevadas frequent, Plumas, Diamond Mountain and Lassen Peak National Forests; 

 near Quincy (Plumas County), mountains east of Chico and Oroville (Butte County), 

 Yuba River at 4.500 to 5.500 feet, Donner Lake, Lake Tahoe National Forest. Emigrant 

 Gap (Flacer County), Lake Tahoe, Placerville (Eldorado County), Stanislaus National 

 Forest, frequent at 6,500 to 8,500 feet; Mud Springs (Amador County), Yosemite Valley, 

 mountains of Fresno County at 8,000 feet, South Fork King's River, Middle Fork Kaweah 

 River at 8.000 feet, Kaweah River road below Mineral King and between Kern River lakes 

 and Trout Meadows ; southern California coast ranges, hills of Santa Clara County up to 

 1,000 feet, ridges west of Los Gatos, Santa Lucia Mountains at 3,000 to 4.000 feet, San 

 Rafael Mountains, San Bernardino Mountains at Bear Valley and elsewhere, San Jacinto 

 Mountains, abundant at 5,000 to 9,000 feet in Tahquitz Valley and elsewhere. The 

 variety villosa Sudworth occurs with the type, especially on the headwaters of the Colum- 

 bia in British Columbia, Montana, and Idaho ; in Washington and Oregon chiefly west of 

 the Cascades and in the southern California coast ranges. 



The distribution in Montana and Idaho will be described in a later publica- 

 tion. 



OCCURRENCE. 



Near streams on low and' high mountain slopes and on moist benches ; in dryish to 

 moist gravelly soils at high levels, and in rich, sandy, or gravelly soils at lower ele- 

 vations, where it is largest. Forms large, dense, pure shrubby thicket in higher range 

 within upper white fir and red fir belt, and nearly pure stands on limited areas lower 

 down, where it often occurs with scattered Douglas fir and western dogwood ; some- 

 times especially abundant on cutover and burned Douglas fir lands. 



Climatic Conditions. — In lower range, similar to those of Douglas fir, but in higher 

 range it endures a climate like that of California red fir. 



Tolerance. — Intolerant of shade. 



Reproduction. — Abundant seeder and scattered seedlings frequent in moist mineral soil 

 and humus. 



Western Choke Cherry. 

 Prunus demissa (Nutt. ) Walpers. 



DISTINGUISHING CHARACTERISTICS. 



It is desirable to establish for Primus demissa the more distinctive name 

 of " western choke cherry," in place of " choke cherry," its ordinary field name, 

 since the latter is also applied to the closely related eastern Prunus virginiana 

 Linnaeus, of which it is held by some to be a geographical form or a variety. 



Very commonly a short or tall tree-like shrub (in dense thickets), from 4 

 to 10 feet high, or, in rich, moist situations, a slender, crooked-stemmed tree 

 from 20 to 25 feet high and from 6 to S inches through. 



Bruised twigs, leaves, and green bark have a strong scent, similar to that 

 of peach-pits. Season's twigs (greenish, smooth or minutely hairy at first) 

 are smooth and light reddish brown, with pointed, light brown buds. Bark, 

 smooth and gray on old trunks and brown on young ones, is irregularly seamed 

 and rough, with hard, deep reddish-brown scales. Mature leaves (fig. 167) 

 are thick, somewhat leathery, deep, dull green ; smooth and shiny on their 

 upper sides; usually more or less minutely hairy and pale beneath (occasionally 

 smooth) ; the borders have straight, sharp teeth. The white flowers are borne 

 in dense cylindrical clusters, as are also the shiny blackish cherries, which 



