Rocky Mountain Maple

Rocky Mountian Maple (Acer glabrum)

Rocky Mountain Maple

(Acer glabrum)


Family: Aceraceae or Maple

Leaves: Opposite; simple; 3" to 5" wide and long; deciduous; 3- to 5-lobed or occasionally separated into 3 separate leaflets; sharply and doubly serrate margin; dark-green above and paler beneath; glabrous; petiole 1" to 4" long, slender, red; fall color yellow to a muted red.

Twigs/buds: Twigs slender; glabrous; green to red-brown. Buds 1/8" to 1/4" long, red, glabrous, one pair of scales visible.

Flowers/fruit: Flowers mostly dioecious (some perfect); yellow-green; no petals; small, inconspicuous; appearing in late spring after leaves. Fruit a samara; U-shaped, with wings nearly parallel, 3/4" to 1" long; pink when mature in summer; becoming light brown and wrinkled in fall.

Bark: Thin and fairly smooth; red-brown.

Wood: Unimportant; diffuse-porous; hard; dense.

General: A small tree native from the western Great Plains west to Oregon and Washington and from the Mexican border through most of British Columbia, including mountainous portions of Utah and the Intermountain West. Prefers moist, protected sites along streams. Shade tolerant.

Landscape Uses: This shrubby tree is rarely planted in cultivated landscapes, maybe because it is not very common in nurseries. Plant in moist protected areas or in the shade of other trees, especially in warm valley sites. Should be fairly tolerant of high soil pH. Zones 4(3?)-7.

Rocky Mountain Maple leaves
Rocky Mountain Maple fruit (Samaras)
Native Rocky Mountain Maple crown
Fruit (Samaras)
Crown, Native