True mountain-mahogany is ordinarily a bushy shrub 2 to 10 feet high, rarely 

 becoming a small tree, up to 20 feet tall, with birchlike, thiekish, more or less 

 persistent leaves. It bears a number of local names, most of which are indefinite 

 or inaccurate, including alder, blackbrush, deerbrush, sweetbrier, and tallow- 

 brush. The almost universal name for the species in Utah is birchleaf (moun- 

 tain-) mahogany, which is, however, more fittingly applied to C. beluloides 

 (syn. C. betulaefoliux) , a similar species with birchlike leaves. 



None of the other species of Ocrcocafpus has a wider distribution than does 

 C. montanus. Its range extends from. South Dakota and Montana to New Mexico, 

 northeastern California, and Oregon. It ordinarily occurs at elevations between 

 4,000 and 10,000 feet, either in coarse, sometimes poor, shallow soil on dry slopes 

 and ridges or in the slightly moister, deeper soils of depressions and canyon 

 bottoms. It may also be found on northern slopes at lower elevations. It is 

 frequently associated with Gambel oak, juniper, piiion, ponderosa pine, service- 

 1 terry, bitterbrush, manzanita, and various species of ceanothus, rabbitbrush, 

 and sagebrush, growing for the most part in distinctly browse types. 1 True 

 mountain-mahogany is sparsely distributed over much of its range but, especially 

 in central and southern Utah and in portions of Colorado and the Southwest, 

 it is often the dominant species of the association and, in localized areas else- 

 where, it is common enough to be an important constituent of the forage supply. 



Ordinarily this shrub ranks as good, very good, or sometimes even excellent 

 browse for all classes of livestock, being held in higher esteem, on the whole, in 

 Utah and the Southwest than in other parts of its range. It is also one of 

 the most valuable winter feeds for deer. 



The leaves of this bush attain full size and the plant is suitable for grazing 

 early in the season but, like those of many other shrubs, they are utilized 

 mostly after midsummer. The leaves normally remain on the plant and 

 are palatable until late fall. In Utah, true mountain-mahogany is practically 

 defoliated by the middle of October. Of course, if an unusual drought occurs 

 or the plants are diseased the leaves dry up early and lose much of their 

 palatability or else drop entirely and prematurely from the bushes. The 

 twigs are palatable yearlong and, wherever available, are grazed with relish. 

 Frequently true mountain-mahogany grows at elevations above the winter 

 range of domestic livestock, which limits its use to some extent. Sheep 

 usually eat all the leaves and only part of the twigs within reach ; goats 

 devour both leaves and twigs, while cattle graze the shrub more moderately. 

 Deer and elk eat the leaves and twigs in summer and the twigs in winter. 



This species withstands close grazing very well ; in fact, the desirability 

 has been suggested of permitting sufficiently close grazing to make the plants 

 bushy and spreading, thus preventing the development of the arborescent 

 habit which would normally occur under the best growth conditions. How- 

 ever, such grazing by any class of livestock, except goats, would: result in 

 overgrazing of the herbaceous vegetation and subsequent erosion. Continued 

 overgrazing of true mountain-mahogany seriously affects forage production 

 and may even kill the plants. 



The branchlets are sparingly soft-hairy when young and inclined to be 

 reddish in color. The slender, rigid, upright branches and twigs are gray or 

 brownish and become marked with conspicuous ringlike leaf scars. The 

 thiekish, conspicuously veined leaves, broadest at the middle and toothed on 

 the margins, are dark green with a tinge of yellow, and somewhat closely 

 resemble those of some birch species. They vary in size in different plants 

 and, to some extent, on the same plant. Lance-shaped, sharp-pointed bracts 

 (stipules) at the base of the leafstalks, from about one-eighth to one-fourth 

 of an inch long, are present for a short time after the appearance of the leaf, 

 but soon drop off. By the time the seed is mature, the calyx tube which 

 partially encloses it has become thin, chestnut-brown, spindle-shaped, only 

 slightly hairy, and deeply cleft from the top down one side. The "seed" is 

 somewhat leathery, grooved on the back, covered with long white hairs, and 

 tipped by a long feathery tail. True mountain-mahogany flowers practically 

 throughout June and most of the seeds mature by mid-August. The seed 

 habits are generally strong. 



1 Dayton, W. A. IMPORTANT WESTERN BROWSE PLANTS. U. S. Dept. Agr. Misc. Pub. 

 101, 214 pp., illus. 1931. 



