400 FOREST TREES OF THE PACIFIC SLOPE. 



Longevity. — Not fully determined, but undoubtedly short-lived. One tree 7A 

 inches in diameter showed an age of 43 years. Maturity is doubtless reached in 

 about 100 years. 



RANGE. 



• 



California (from Sacramento River in Mendocino County along coast ranges to San 

 Luis Obispo County ; western foothills of Sierras to northern slopes of Tejon Pass in 

 Kern County; Antelope Valley north of San Gabriel Mountains in Los Angeles County). 



Worth Coast Ranges: Lower foothills (500 to 2,000 feet) northward into Mendocino 

 County, Shasta County, at least to Redding in Sacramento River Valley. Locally noted 

 on Russian River (Mendocino County) ; in canyons and on hills near TJkiah : at Lewiston 

 and on Canyon Creek (Trinity County) ; hill between Shasta (town) and Whiskeytown 

 (Shasta County) ; lower hills of Stony Creek National Forest; valleys south of Clear 

 Lake (Lake County) ; Mount Tamalpais (Marin County). South Coast Ranges: Probably 

 throughout lower foothills to San Luis Obispo Mountains, but noted only on seaward 

 range west of Santa Clara Valley (500 to 1,500 feet), where it is common; near Santa 

 Cruz ; foothills of Santa Cruz Mountains ; near Monterey on foothills just above Carmel 

 Mission; Monterey National Forest (Santa Lucia Mountains), at 600 to 4,000 feet, but 

 not common, in basins of Sur, Carmelo, and Arroyo Seco rivers ; San Luis Obispo National 

 Forest, only in basin of Salinas River. Sierra Foothills: Common from Shasta County to 

 Tehachapi Mountains ; in the north, at 500 to 2,000 feet, and in the south, at 1,000 to 

 3,000 feet. Locally noted in Shasta County; near Chico (Butte County); near lone 

 (Amador County) at 200 to 5,000 feet; Stanislaus National Forest, throughout lower 

 belt; Northfork and vicinity (Madera County) ; South Fork of King's River, below Mill- 

 wood ; Kaweah River, foothills ; Kern River basin, below oaks ; at Havilah ; Kernville 

 to Walker Basin. Southern Cross Ranges: Abundant in Tehachapi Mountains in canyons 

 and nearly up to summits ; extends eastward and southward to the north slopes of Santa 

 Barbara Mountains above Antelope Valley, where it occurs in basin of Elizabeth Lake at 

 2,400 to 4,500 feet, reaching the foot of Sawmill Mountain. Locally noted from Havilah 

 to Fort Tejon and in Canada de las Uvas, and reported on south slope of Santa Barbara 

 Mountains in Matilija Creek basin. 



OCCURRENCE. 



Foothill and lower mountain slopes ; frequent on borders of streams and canyon sides, 

 in dry gravelly soils. Forms spreading clumps interspersed with scrub oak, redbud, 

 occasional live oak, blue oak, and gray pine, manzanita, and other chaparral brush ; largest 

 in sheltered coves and gulches. 



Climatic Conditions. — Similar to those of blue oak and gray pine. 



Tolerance. — Seedlings endure slight shade for several years, but later growth demands 

 full light. 



Reproduction. — Fairly abundant seeder. Young plants moderately frequent. Seed 

 germinates only when it is well covered in soil. 



Family BHAMNACE5!. 



Rhamnacese is popularly known as the buckthorn family, which is widely 

 known chiefly from its representative genus Rharunus, an exotic species which 

 is particularly famous as a medicinal plant. They are all small trees or shrubs, 

 some of them generally distributed throughout the world. They are character- 

 ized by their bitter bark, their often scaleless (naked) buds, their single-bladed 

 leaves, evergreen or shed every autumn, and their small, greenish, usually 

 bisexual flowers and berry-like fruits. Six genera, containing trees, occur in the 

 Tnited States, and two of them, Ceanothus and Rhamnus, are represented by 

 eastern and Pacific species. 



RHAMNUS. BUCKTHORNS. 



The buckthorns form a large group containing trees and shrubs characterized 

 by their intensely bitter, pungent bark and twigs. The twigs do not have 

 strictly terminal or end buds, the last bud being a side one at the base of the 

 last leaf-stein. The leaves, evergreen or shed each autumn, occur singly on the 



