FOREST TREES OF THE PACIFIC SLOPE. 435 



crown ; less frequently, from TIO to 40 feet high, and from 10 to 15 inches in 

 diameter ; exceptionally large individuals are Bometimes 2 feet through. At 

 higher altitudes chiefly a tall, many-stemmed shrub. Lower 1. ranches arc often 

 arched and drooping, while large limbs are frequently sharply crooked ("el- 

 bows"), owing to upright shoots growing out from points where the limbs are 

 broken off. Bark of tree forms thin, dark yellowish-brown — sometimes faintly 

 reddish— rather regularly and deeply cut into a network of connected, narrow 

 ridges. Twigs of a season's growth are smooth, sparsely white-hairy at first, 

 shiny reddish brown, somewhat angled — strongly so when young — and marked 

 with large, horseshoe-like leaf-sears, which have 5 minute pits i ends of woody 

 fibers of the parted leaf-stem I. Mature leaves (fig. 207), shed in autumn, are 

 smooth throughout, composed of 3 to 9 leaflets which are lighter green beneath. 

 Mature "berries" (fig. 207), whitish with a chalky bloom which, when rubbed 

 off, reveals a smooth, blue-black skin; the berries are 1 to .", seeded, sweetish and 

 edible." The seeds are disseminated very largely by birds and a few mammals 

 which eat the berries for the juicy pulp. Wood, pale brownish yellow, with thin, 

 whitish sapwood; usually wide-grained, rather light and soft, and very brittle. 

 Not used for economic purposes. 



Longevity. — The age limits of the largest trees are not fully known, but it is 

 undoubtedly a short-lived tree. Smaller trunks studied indicate very rapid 

 height and diameter growth, while a record of one planted tree shows it to have 

 attained about 40 feet in height and 28 inches in diameter in approximately 

 fifty years. Record of a forest-grown tree 12 inches in diameter shows an age of 

 thirty-five years. 



From southern British Columbia i Fraser River) and Vancouver Island to the southern 

 borders of California and eastward to the Blue Mountains in Oregon and the Wasatch 

 Mountains in Utah. 



OCCURRENCE. 



Bottoms of mountain canyons, valleys, and adjacent slopes, on mountain streams, in 

 ravines, and moist hillsides; in rich, porous, gravelly soils. Largest in northern low val- 

 leys; shrubby at high levels. Scattered among Douglas fir. western yellow pine, grand 

 fir, madrona, red alder, broadleaf maple (at north), and sometimes with live oak, Cali- 

 fornia sycamore, and white alder (at south). 



Climatic CONDITIONS. — Similar to those of Douglas fir (in northern range) and Cali- 

 fornia syi-amore (in southern range). 



Tolerance. — Endures very little shade at any period. 



Reproduction.— Abundant seeder; reproduction frequent, but scattered. 



Mexican Elder. 

 gambucus mexicana I'resl. 



DISTINGUISHING CHARACTERISTICS. 



Mexican elder is known in the field simply as "elder," but it should have a 

 more distinctive common name, and Mexican elder Is proposed. 



Nearly always of tree form, from 15 to 25 feet high and from 6 to 10 inches 

 through above the swelled base; the clear trunk, with yellowish brown (some- 

 times faintly reddish), finely ridged bark, is short; the crown is broad and 

 rounded. Lower branches arched, drooping, and angled, as in the blue elder- 

 berry. Twigs of a season's growth nearly always with dense, whitish, tine 

 hairs when young, pale reddish brown and usually smooth. Mature leaves, 

 very similar in general appearance to those of the preceding elder, containing 



° Settlers use the berries as a fruit, which is excellent when cooked. 



