18 MISC, PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
BIRCH FAMILY (BETULACEAE) 
ALDERS (ALNUS SPP.) 
About nine species of alder, mostly shrubs or small trees, occur 
on ranges of the West. Probably all are grazed to an appreciable 
extent, at least by cattle, which are much more apt to linger where 
alders grow than are sheep or goats. 
The palatability of alders is not, in general, high; because of 
their abundance, however, especially in moist or wet meadows and 
along streams, they are sometimes an important secondary constit- 
uent of the forage crop. They propagate chiefly by underground 
rhizomes or suckers, often forming hardly penetrable thickets which, 
hindering ingress of stock and tending by competition to force the 
foliage upwards, decrease the browse value of this genus. The roots, 
like those of legumes, often bear nodules of nitrogen-fixing bacteria; 
it would seem likely that this symbiotic relationship would be re- 
flected in a relatively high protein content of the herbage. With 
one or possibly two exceptions the small size of western species of 
alder precludes their use in the lumber trade and most of them 
appear to have more significance as watershed protection and forage 
than silviculturally. 
Red alder (Alnus rubra, syn. A. oregona), or Oregon alder, is 
one of the most abundant and widely distributed species and in 
many localities its leaves and younger twigs are ranked as fair 
browse for cattle and sheep. Another of the commonest western 
alders is A. sinuata, with leaves thinner, more delicate, and more 
palatable than those of most of its congeners. ‘This is held to be 
a fair sheep browse in the Wenatchee Mountains of Washington. 
Mountain alder (A. tenuifolia), possibly better called thinleaf 
alder, is perhaps the commonest of the montane western alders and 
is one of the most palatable species of the genus for sheep. In 
central and northern Idaho and in many parts of the Northwest 
generally this is frequently considered a fair sheep browse. 
In Alaska and the far North as a whole alders are often an im- 
portant browse for moose, and Hadwen and Palmer (57) mention 
A. alnobetula as furnishing some feed in summer for reindeer. 
BIRCHES (BETULA SPP.) 
There are about 14 western birch species, nearly all of which 
usually occur as shrubs or small trees. A number of the shrubby 
western birches are taken fairly well by livestock, the juices of these 
plants appearing to be rather blander than those of alders, their 
foliage mostly more delicate, and the general palatability greater. 
Red birch (B. fontinalis), often called water birch and mountain 
birch, a common western shrub, is an important browse species on 
many sheep and goat ranges, its palatability ranging from fair to 
very good. 
Resin birch (B. glandulosa), often called mountain bog birch, 
one of the commonest and most widely distributed western birches, 
ordinarily does not exceed 6 or 7 feet in height. It occurs in the 
mountains up to subalpine or alpine elevations. Its palatability 1s 
generally considered to be good for both cattle and sheep but it is 
often inaccessible because of the boggy sites it inhabits. In north- 
