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Acer glabrum is often confused with:: Acer rubrum
Native alternative(s) for Acer glabrum:: Acer rubrum
Plants that fill a similar niche:: Quercus nigra; Ulmus alata; Ulmus americana
Acer glabrum has some common insect problems:: Common Insect Pests of Maple in North Carolina
Acer glabrum has some common disease problems:: Common Disease Pests of Maple in North Carolina

Rocky Maple Acer glabrum

Other Common Name(s):

Previously known as:

Acer glabrum subsp. typicum
Acer glabrum var. typicum

Phonetic Spelling

AY-ser GLAH-brum

Description

Rocky Mountain maple is a deciduous shrub or small shade tree in the maple family (Sapindaceae) and is native to western North America from Alaska south to California and west to Nebraska and south to New Mexico. The specific epithet means smooth, without hair, referring to its smooth stems and leaves. The species is named after David Douglas, a Scottish botanist who in addition to this tree, is also known for the Douglas fir.

This tree will grow 12-30 feet in height and spread 10 to 20 feet wide. It usually has a multi-trunk habit and a shrub-like growth and a narrow crown in more open areas. It can be tall and spindly in closer stands of trees. Can withstand sandy, loamy, and heavy clay acidic soils, prefers well-drained soil and needs lots of organic matter. It performs best in semi-shade to shade. Plant in a location sheltered from strong winds, frost, and afternoon sun. This is a relatively low-maintenance tree, and should only be pruned in summer after the leaves have fully developed, as it may 'bleed' sap if pruned in late winter or early spring.

There are three varieties depending on what region they are growing in. They are listed below.

It is primarily grown for its ornamental red fruit in the late summer and fall and its interesting red twigs that stand out, particularly in the winter. The fall color is knock-out yellow-to-red.

Works well for erosion control, in a woodland garden and as an understory tree. Best grown in its native habitat and would not be appropriate for the southeast.

Insects, Diseases, and Other Plant Problems: No significant insect or disease problems. In alkaline soils, it can develop manganese chlorosis. Watch for aphids, leafhoppers, borers, scale, and caterpillars. Also note that verticillium wilt attacks the vascular system and can be fatal. Canker, fungal leaf spot, and root rots may also occur. Wind and ice may break some branches.

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common maple diseases and insect pests.

See this plant in the following landscape:

Cultivars / Varieties:

var. diffusum
Found in dry mountain slopes
var. douglasii
Found coastal southeast Alaska and British Columbia, to southern Oregon; east to Idaho and Montana.
var. glabrum
Variety found in non-coastal regions of the west.

var. diffusum, var. douglasii, var. glabrum

Tags:

#deciduous #small tree #shade tree #samaras #shade garden #cover plant #low maintenance #winter interest #fall interest #erosion control #small mammals #fast growing #nighttime garden #children's garden #red fruits #red stems #pollinator plant #nesting sites #multitrunked #larval host plant #fall color yellow #clay soils tolerant #bird friendly #fall color red #butterfly friendly #imperial moth #wildlife friendly #woodland

Form — Form dr-home CC BY-NC 4.0

var. diffusum form — var. diffusum, form Stan Shebs CC BY-SA 3.0

var. diffusum flower — var. diffusum, flower Stan Shebs CC BY-SA 3.0

var. diffusum red samara — var. diffusum, red samara Stan Shebs CC BY-SA 3.0

Samaras — Samaras Walter Siegmund (talk) CC BY-SA 3.0

Close up of the leaf — Close up of the leaf Walter Siegmund CC BY-SA 3.0

Underside of leaf — Underside of leaf Kate McKeown CC BY-NC 4.0

Var. douglasii leaf — Var douglasii leaf brewbooks CC-BY-SA 2.0

var diffusum form — var diffusum form Stan Shebs CC BY-SA 3.0

var. douglasii samara — var. douglasii samara Thayne Tuason CC BY-SA 4.0

var. diffusum smooth bark — var. diffusum, smooth bark Stan Shebs CC BY-SA 3.0

Fissured bark — Fissured bark sethberes CC BY-NC 4.0

Cultivars / Varieties:

var. diffusum
Found in dry mountain slopes
var. douglasii
Found coastal southeast Alaska and British Columbia, to southern Oregon; east to Idaho and Montana.
var. glabrum
Variety found in non-coastal regions of the west.

var. diffusum, var. douglasii, var. glabrum

Tags:

#deciduous #small tree #shade tree #samaras #shade garden #cover plant #low maintenance #winter interest #fall interest #erosion control #small mammals #fast growing #nighttime garden #children's garden #red fruits #red stems #pollinator plant #nesting sites #multitrunked #larval host plant #fall color yellow #clay soils tolerant #bird friendly #fall color red #butterfly friendly #imperial moth #wildlife friendly #woodland

Attributes:
Genus:

Acer

Species:

glabrum

Family:

Sapindaceae

Life Cycle:

Woody

Recommended Propagation Strategy:

Seed

Country Or Region Of Origin:

Western North America

Distribution:

Alaska, Alberta, Arizona, British Columbia, California, Colorado, Idaho, Mexico Northeast, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Utah, Washington, Wyoming, Yukon

Wildlife Value:

Members of the genus Acer support Imperial Moth (Eacles imperialis) larvae which have one brood per season and appear from April-October in the south. Adult Imperial Moths do not feed. Food and shelter to wildlife

Play Value:

Attracts Pollinators

Pieces Used in Games

Wildlife Cover/Habitat

Wildlife Food Source

Wildlife Nesting

Particularly Resistant To (Insects/Diseases/Other Problems):

erosion

Dimensions:

Height: 12 ft. 0 in. - 30 ft. 0 in.

Width: 10 ft. 0 in. - 20 ft. 0 in.

Whole Plant Traits:
Plant Type:

Shrub

Tree

Woody Plant Leaf Characteristics:

Deciduous

Habit/Form:

Erect

Multi-trunked

Rounded

Spreading

Growth Rate:

Rapid

Maintenance:

Low

Texture:

Medium

Cultural Conditions:
Light:

Dappled Sunlight (Shade through upper canopy all day)

Full sun (6 or more hours of direct sunlight a day)

Partial Shade (Direct sunlight only part of the day, 2-6 hours)

Soil Texture:

Clay

High Organic Matter

Loam (Silt)

Sand

Soil pH:

Acid (<6.0)

Soil Drainage:

Good Drainage

Moist

Occasionally Dry

Very Dry

USDA Plant Hardiness Zone:

3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b

Fruit:
Fruit Color:

Brown/Copper

Green

Pink

Red/Burgundy

Display/Harvest Time:

Fall

Summer

Fruit Type:

Samara

Fruit Length:

< 1 inch

Fruit Description:

Red winged samaras. This plant has green, insignificant flowers in April, which are pollinated by insects and followed by showy red winged samaras in late summer. Plant is dioecious.

Flowers:
Flower Color:

Green

Flower Inflorescence:

Cyme

Insignificant

Flower Value To Gardener:

Fragrant

Flower Bloom Time:

Spring

Flower Size:

< 1 inch

Flower Description:

Green, insignificant flowers in April in terminal drooping cymes. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown for pollination to occur.

Leaves:
Woody Plant Leaf Characteristics:

Deciduous

Leaf Color:

Gold/Yellow

Green

Pink

Red/Burgundy

Deciduous Leaf Fall Color:

Gold/Yellow

Red/Burgundy

Leaf Margin:

Lobed

Hairs Present:

No

Leaf Width:

1-3 inches

Leaf Description:

Lobed leaves green most of the year turn yellow to brick red in the fall.

Bark:
Bark Color:

Dark Brown

Dark Gray

Light Brown

Light Gray

Surface/Attachment:

Fissured

Smooth

Bark Description:

Smooth, brownish gray bark becomes fissured with age

Stem:
Stem Color:

Red/Burgundy

Stem Is Aromatic:

No

Stem Surface:

Smooth (glabrous)

Stem Description:

The stems are smooth and red in winter.

Landscape:
Landscape Location:

Slope/Bank

Woodland

Landscape Theme:

Butterfly Garden

Children's Garden

Nighttime Garden

Pollinator Garden

Shade Garden

Winter Garden

Design Feature:

Shade Tree

Understory Tree

Attracts:

Butterflies

Moths

Pollinators

Small Mammals

Songbirds

Resistance To Challenges:

Diseases

Erosion

Insect Pests