FOREST TREES OF THE PACIFIC SLOPE. 351 



Longevity. — Not fully determined. It grows very persistently and appears to 

 be long-lived. A single stem 5A inches in diameter was 48 years old. 



RANGE. 



California coast ranges and Sierras (chaparral holt I southward from Mendocino and 

 Shasta counties to northern Lower California ; also on southern California coast islands. 



California. — Coast ranges northward on coast to Mendocino County, and to Trinity 

 Mountains on inland ranges, where it has been noted as far north as between Redding 

 and Whiskey town (Shasta County). In Sierras, on foothills in Lassen Peak, Diamond 

 Mountain. Plumas, Tahoe, and Stanislaus National forests. Southward in coast ranges 

 to San Francisco Pay. and in southern coast ranges eastward to San Bernardino; also in 

 islands off southern coast. South of Monterey Bay, noted on Point Pinos, in Pescadero and 

 a few other canyons, and in Santa Lucia Mountains in chaparral of Sur, Carmelo, Arroyo 

 Seco, San Antonio, and Nacimiento river basins from sea-level to 4,250 feet. San Luis 

 Obispo National Forest (to southeast), from 250 to 2,250 feet elevation in watersheds of 

 Carriso, Salinas, Santa Margarita, San Luis. Arroyo Grande, and lluasna rivers. Santa 

 Barbara National Forest, below 3,000 feet in watersheds of Santa Maria. Santa Ynez, 

 Santa Barbara, Matili.ja, Piru-Sespe, Newhall, and Elizabeth rivers. Santa Ana range. 

 All coast islands except San Clemente. General in San Gabriel National Forest : noted on 

 south slope Sierra Liebre Range, near Pasadena, Arroyo Seco. San Bernardino Moun- 

 tains. San Jacinto Mountains and Palomar, Balkan, and Cuyamaca Mountains i San 

 Diego County i. Mexican boundary, noted on west slope of coast range up to 4,500 feet. 



Lower California. — Northern part, in Hanson, Laguiia, and San Pedro Martir ranges. 



OCCURRENCE. 



Frequent on north slopes of low mountains and foothills in vicinity of watercourses, in 

 gulches, or on exposed sea cliffs; in dry, rocky, and gravelly soils. Grows in scattered, 

 pure clumps and patches on mainland slopes (shrubby), and in small pure stands, as a 

 tree, in its island range. 



Climatic Conditions. — Similar to holly-leaf cherry. Tolerance and other silvical 

 characteristics undetermined. 



Reproduction. — Very prolific seeder. Young plants abundant in soil-filled crevices, 

 pockets, and in other places of lodgment. 



PRUNTJS. CHERRIES AND PLUMS. 



As here constituted, a large group containing such well-known and widely 

 distributed trees and shrubs as the plums, peaches, almonds, apricots, and 

 cherries, most of which do not produce useful timber, but are among the most 

 valuable fruit trees. The plums and cherries are the only native trees of the 

 group to be considered here. 



For the sake of reducing the number of generic names, the latter-day practice 

 of subdividing this long-maintained composite group into Primus (including the 

 plums only) .and Cerasus (including only the cherries) will not be followed. 

 It is thought best to treat these trees under I'm mix, as has been done for a long 

 time. The cherries differ from plums principally in having a rounded fruit 

 seed or "stone" in place of more or less liat seeds: plum fruits are. moreover, 

 usually covered with an easily removed, whitish bloom, which is absent from 

 cherry fruits. 



Primus contains but one tree species (black cherry) of commercial impor- 

 tance; the remaining representatives are small trees or shrubs of little economic 

 use. Some of the western plums and cherries, however, are useful in helping 

 to form protective '-overs on otherwise thinly clad mountain slopes. 



Wood of the plums and cherries is fine-grained, dense, evenly and finely 

 porous, rather heavy, and rich light or dark brown. Green twigs and bark are 

 characteristically bitter, and have, when crushed, a more or less strong peach- 

 pit odor possessed by no other group of plants. 



