Rocky Mountain maple (Acer glabrum)

First place champion in Crawford.

Species info:

Leaves: Opposite, simple, 3 to 5 inches in diameter, sharply 3 to 5-lobed or rarely 3-parted or even divided

Leaflets: N/A (simple leaves)

Leaf Surface: Shiny dark green above, paler or whitish beneath

Twig: Reddish brown, slender

Bark: Gray or brown; smooth, thin

Flowers: Small, greenish-yellow clusters appearing with new leaves in early spring

Fruit: A 1-seeded winged samara with wings spread slightly; reddish, turning light brown

Botanical: Acer glabrum

Family: Sapindaceae

Mature Height: Typically around 35 feet

Canopy Spread: 25–35 feet, depending on cultivar.

Foliage Type: Deciduous

Tree Shape: Shrubby or small tree with upright branching

Flowers: Inconspicuous

Fruit: None

Fall Color: Attractive, red or yellow

Water Use: Moderate to high; prefers moist, well-drained soils

Hardiness: Zones 3–7 (depending on cultivar); recommended below 7,500 ft elevation.

Soil Preference: Best in neutral to slightly acidic soils; prone to chlorosis in alkaline conditions (pH > 7.4).

Wildlife Value: Attracts pollinators in spring; samaras eaten by birds and small mammals.

Pests/Pathogens: Generally pest-free.

Colorado Suitability: This Colorado native is recommended for most sites, but prefers moist soils.

Planting recommendation: Conditionally recommended for the Front Range, as it requires acidic soils

Information Sources:

• C. Frank Brockman. Trees of North America. Golden Press. Western Publishing Company, Inc. 1986.

• Stephen Whitney and Elbert L. Little. Western Forests. Chanticleer Press, Inc. 1985.