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Rocky Mountain Maple
Acer glabrum Torry

Reported by Lewis and Clark Expediton at the Lemhi River on 13 Aug 1805.

Rocky Mountain maple is a native, deciduous tall shrub or small tree. It often grows 20 to 30 feet tall, with crown widths from 10 to 20 feet (3-6 m) wide and a stem diameter up to 12 inches, though it can reach 40 feet tall, and 2 feet (0.6 m) in diameter. Rocky Mountain maple is usually tall and spindly in closed stands, with a more dense and brushy growth form in open stands. Though it may have a single dominant stem, Rocky Mountain maple most often occurs as a multi-stemmed shrub 5 to 6.5 feet tall.

Rocky Mountain maple has opposite, ascending to erect branches, rounded twigs, and a narrow crown. The bark of Rocky mountain maple is smooth until maturity, when fissures develop. Rocky mountain maple has a wide, spreading root system with a combination of deep and lateral woody roots .  It may be monoecious, or dioecious.  Flowers are borne in loose terminal cymes arising from lateral buds  and grow in drooping clusters. The paired seeds are winged samaras. Seeds are 0.16 to 0.2 inch  long and samaras are 0.08 to 0.12 inch long..

Rocky Mountain maple occurs on wetlands, stream banks, canyons, and upland mountain slopes Though it occurs on both moist and dry sites. Rocky Mountain maple is more closely tied to drainages in arid zones of its distribution, but occurs on drier exposures northward and at higher elevations.  On upland sites, Rocky Mountain maple grows on lower, mid, and upper slopes , alluvial terraces, summits, ridge tops, snow chutes, and talus slopes.  (Source)

Medicinal Uses: A bark decoction was used as a poison antidote. 

Other Uses: Maples generally have a good, strong and pliable wood. The rocky mountain maple's wood was widely used by the native peoples of the central west coast of North America. It was used for making miniature paddles that served as rattles on ceremonial costumes. It was also used for making drying racks, drum hoops, snowshoes, spears, pegs, toys and masks. Women used it to make their sweathouses because it is easy to bend and for the same reason it was also often used to make a child’s first bow. The fibrous bark was woven into mats and into rope.  

Value to Animals:

Rocky Mountain maple is generally an important browse species for wildlife throughout its range.  Rocky Mountain maple is valuable for mule deer, moose, and elk  in the northern Rockies. Big game animals generally consume the buds and current annual twig growth. However, Rocky Mountain maple often grows quickly out of reach.Rocky Mountain maple is a principal forage species of shrub fields in the northern Rockies, which provide important winter range for deer and elk. Though it is also browsed in the summer, Rocky Mountain may be heavily used in late fall and winter by mule deer and white-tailed deer. It is also important winter browse for bighorn sheep, and elk. Rocky Mountain maple is particularly important winter and spring moose browse.

Ruffed grouse in Idaho eat the leaves and buds of Rocky Mountain maple . Rocky Mountain maple seeds are also important forage for grosbeaks and small mammals.

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