Tuesday, October 30, 2007

American Elm








American Elm
(Ulmus americana)

General Description
The state tree of North Dakota. A large vase-shaped tree
adapted to a wide variety of sites. No longer recom-
mended because of its susceptibility to Dutch Elm Disease.
The largest tree in North Dakota is 62 feet tall with a
canopy spread of 74 feet.

Leaves and Buds
Bud Arrangement - Alternate.
Bud Color - Smooth, sharp-pointed, and reddish-brown.
Bud Size - Lateral buds are small, 1/4 inch long.
Leaf Type and Shape - Simple, unequal at the base,
ovate-oblong.
Leaf Margins - Doubly-serrate.
Leaf Surface - Glabrous to rough above, pubescent or
nearly glabrous beneath.
Leaf Length - 3 to 6 inches.
Leaf Width - 2 to 3 inches.
Leaf Color - Dark-green above, lighter green below; Yello Fall Collor
Flowers and Fruits
Flower Type - Polygamo-monoecious, in fascicles of 3 or 4.
Flower Color - Greenish-red to brownish.
Fruit Type - Winged samara, oval-globose and wafer-like
in appearance, notched.
Fruit Color - Light-green, changing to tan.
Form
Growth Habit - Trunk divides into several erect arching
limbs above, umbrella to vase-shaped.
Texture - Medium-coarse, summer; medium-coarse,
winter.

Crown Height - 45 to 65 feet.

Crown Width - 30 to 50 feet.

Bark Color - Dark gray-brown, with broad ridges and
deep furrows.
Root System - Root spread is greater than height. Root
system is shallow, fibrous, and in dry areas may have a tap
root.
Environmental Requirements
Soils
Soil Texture - Grows best in rich, moist, well-drained soils,
but adapts to a wide range of soil types.
Soil pH - 5.5 to 8.0.
Windbreak Suitability Group - 1, 1K, 3, 4, 4C, 5.
Cold Hardiness
USDA Zone 2.

Water
Drought tolerant, but prolonged drought stress predis-
poses trees to pests. Tolerant of infrequent, short duration
flooding during the growing season.

Light
Full sun to partial shade.

Uses
Conservation/Windbreaks
Tall tree for farmstead and field windbreaks, and riparian
plantings.
Wildlife
Seed, buds, and tender young twigs are used as food by
birds and mammals, particularly deer.
Agroforestry Products
Wood - Used in fine furniture, boxes, barrels, and crates.
Good for firewood, but hard to split.
Medicinal - Extracts of some Ulmus species have been used
as a demulcent, an astringent, a diuretic, and for inflam-
mation, burns, cold sores and wound treatments.
Urban/Recreational
A favorite tree for all sites, but no longer recommended
because of Dutch Elm Disease.
Cultivated Varieties
Ulmus americana ‘Ascendens’ and ‘Augustine’ - Cultivars
with columnar form.
U. americana ‘Lake City’, ‘Moline’, and ‘Minneapolis Park’
- Variably vase-shaped. Due to susceptibility to Dutch Elm
disease, the above cultivars are rarely planted (see
Japanese Elm and Siberian Elm for Dutch Elm disease
resistant cultivars.)
Related Species
David Elm (U. davidiana)
European White Elm (Ulmus laevis)
Japanese Elm (U. davidiana var. japonica)
Lincoln Elm (U. rubra ‘Lincoln’)
Rock Elm (U. thomasii)
Slippery Elm (U. rubra)
Pests
Besides Dutch Elm disease, common diseases include
wetwood, black leaf spot, and branch cankers. Common
insect pests include cankerworms and aphids. Deer
browse damage can be serious on young trees.

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