FOREST TREES OF THE PACIFIC SLOPE. 197 



10 or 12 miles east of Mendocino (western limits) ; also near Canto and Laytouville 

 and near Willets and a few miles north of Ridgewood Summit (between Willets and 

 Ukiah). Trinity County, noted east to canyon between Lewiston and Whiskeytown at 

 2,000 feet, Canyon Creek from Dedrick to Alpine lakes (5,600 feet), in gulches of Carl, 

 Salt, and Dutch Creeks between Junction and Hay Fork and in gulches between Posti 

 Ranch and South Fork of Trinity River, ('niusn County: On Snow Mountain and in deep 

 canyons on Elk Mountain. Lake County: Noted on Sanhedrin Mountain, and east side of 

 Mount St. Helena in canyon between Tollhouse and Middletown. Mount Shasta National 

 Forest only detected east to headwaters of Sacramento River (Siskiyou County) and 

 McCloud River (Shasta County) at 15 miles above Baird, at 3,000 to 0,000 feet. Not 

 known on Mount Shasta. Lassen Peak, Plumas and Lake Tahoe National Forests infre- 

 quent in yellow pine belt of central plateau region and wet canyons of west side of 

 main range ; noted in Placer County just south of North Fork American River east of 

 Iowa Hill, a few miles east of Forest Hill, and in Devil's Canyon between Forest Hill 

 and Colfax. Stanislaus National Forest, infrequent in red fir belt ; noted in vicinity of 

 Mutton Canyon and Deep Canyon (branches of Pilot Creek, a tributary of Rubicon 

 River i at 4.o«)0 feet; Big Iowa Canyon (tributary South Fork American River) at 

 3,000 feet, headwaters of Sly Park Creek (tributary of North Fork of Cosumnes River), 

 and North Fork of Webber Creek at* 4,000 feet, at 2,500 to 3,000 feet on the headwaters 

 of Cedar Creek (tributary same river), at 3,500 feet on Clear Creek (tributary Webber 

 Creek), headwaters of Mill Creek (tributary North Fork of Mokelumne River) at 3,500 

 to 4.000 feet. South on west side Sierras at 5,000 to 8,000 feet to Tulare County. Also 

 reported in coast ranges south of San Francisco Bay south to Santa Cruz Mountains. 



OCCURRENCE. 



Near margins of low mountain streams, moist flats and benches, deep ravines and 

 coves, in rich rocky or gravelly soils. Largest in western Oregon, Washington, and 

 British Columbia ; much smaller in eastern range, especially in drier situations. Groves 

 in small groups and singly, scattered sparingly with Douglas fir, grand fir, redwood, tan- 

 bark oak, vine, and broad-leafed maples. 



CLIMATIC Comditions. — Similar to those of Douglas fir (in Pacific range). 



Tolerance. — Exceedingly tolerant of dense shade throughout life ; crown foliage thin 

 and branches low to ground under deep shade ; grows well in partial or full light, but 

 crown and foliage then much more dense. 



Reproduction. — Fairly prolific seeder. Vitality of seeds persistent and germination 

 moderately high. Seedlings only occasional — often rare and mostly in deep shade on 

 wet moss and decaying w 7 ood. . Imperfectly known. 



MONOCO TYLEDOXES. 



The trees which belong to the great class of monocotyledones differ from 

 ordinary trees in not having their woody tissue arranged in annual concentric 

 rings. Instead, the woody, thread-like fibers are scattered apparently irregu- 

 larly throughout the trunk, on a cross-section of which tbe ends of these fibers 

 appear like numerous dots. Another important characteristic is \he single 

 cotyledon or seed-leaf produced by the newly germinated seed. Other tree seed- 

 lings have 2 or more seed-leaves. The veins of monocotyledonous tree leaves 

 .are usually parallel to each other, just as in the leaves of grasses and Indian 

 corn, .also members of this class, in contrast with the feather and net like rein- 

 ing of ordinary tree leaves. To this group belong the palms and yuccas, which 

 are essentially subtropical or tropical plants. The tree palms grow throughout 

 their life with a single unbranched. column-like trunk, at the top of which the 

 leaves are clustered. Tree yuccas are sparingly branched, much as in other 

 trees, but their manner of producing leaves from the ends of the few branches 

 is similar to that of the palms. 



Family PALM-ffi. 



The trees of this family, known as palms, have single, straight, unbranched, 

 cylindrical trunks, crowned by a cluster of spreading, fan-like leaves. The fruit, 

 borne in branched clusters, is berry-like and usually one-seeded — seldom 2 to 3 

 •seeded. 



