American Elm

Recently it has been decimated by Dutch Elm Disease. (Hultman, 1978) This introduced pathogen, Ophiostoma ulmi hit city trees particularly fiercely. Dutch Elm Disease is spread by a beetle typically and is a fungus. Snags with peeling bark from the disease may produce valuable wildlife cover. Gray and fox squirrels feed heavily on flower buds. Fallen mature seeds are used by small rodents and wood ducks. Foliage is taken by white-tailed deer and woodchucks. Cover is used by nesting shrubland birds. (Weeks et al, 2005) Population was ravaged by the Dutch Elm disease, caused by a fungus introduced accidentally about 1930 and spread by European and native elm bark beetles. (NPIN, 2008)

Wildlife uses include seed eating by granivorous birds, bird cover, bird nesting sites, and substrate for insectivorous birds. Seeds feed small mammals. It is a larval host for Mourning Cloak (Nymphalis antiopa), Columbia silkmoth (Hyalophora columbia), Question Mark (Polygonia interrogationis), Painted Lady (Vanessa cardui), and Eastern Comma (Polygonia comma). (NPIN, 2008)

Active growth period is Spring and Summer, and is rapid. The tree is deciduous. Blooming occurs in Early Spring. Fruit/seed period begins in Spring and ends in Spring. (USDA PLANTS, 2009) Flowering occurs in April and May. (Peattie, 1930) Flowering is March to May. Seeds are produced April to May. (Hultman, 1978) Fall coloration is yellow. Large flowers may appear in February further South. (Weeks et al, 2005) Bloom time is February, March, and April. (NPIN, 2008)

This is the most common elm in the eastern US. (Weeks et al, 2005) The tree is reported as widely escaped in Idaho, which is not part of the natural range. It is occasionally cultivated outside its native distribution, and it has escaped sporadically from cultivation. It is also reported as naturalized in Arizona. (FNA, 2006)

USA: AL , AR , CT , DE , FL , GA , IL , IN , IA , KS , KY , LA , ME , MD , MA , MI , MN , MS , MO , MT , NE , NH , NJ , NY , NC , ND , OH , OK , PA , RI , SC , SD , TN , TX , VT , VA , WV , WI , WY , DC (NPIN, 2008)

Canada: MB , NB , NS , ON , PE , QC , SK (NPIN, 2008)

Native Distribution: N.S., s. Man & s.e. Sask. & Crook Co. WY, s. to FL & c. TX (NPIN, 2008)

USDA Native Status: L48(N), CAN(N) (NPIN, 2008)

2 n = 56. (FNA, 2006)

Habitat constitutes rich meadows and stream bottoms along morainal borders. Occasional in red maple swamps back of high dunes. (Peattie, 1930) Most common in bottomlands. (Hultman, 1978) Common in moist to wet, rich woods and flood-plains. (Weeks et al, 2005) Native habitat consists of stream banks and lowland areas. (NPIN, 2008) Habitat includes alluvial woods, swamp forests, deciduous woodlands, fence-rows, pastures, old fields, and waste areas. It is also planted as street trees. Elevation from 0-1400 m. (FNA, 2006)

Lifespan is moderate. (USDA PLANTS, 2009) Formerly it was long-lived. Trees to 400 years old have been documented. It now rarely survives to maturity at 150 years of age because of Dutch Elm Disease. (Weeks et al, 2005)

Overall This is an erect tree. (USDA PLANTS, 2009) The tree is tall with an umbrella-shaped crown. (Peattie, 1930) Large trees are easily recognized by tall, clear trunks, open, spreading crowns, and graceful, drooping limbs that form a vase shape. It often has a buttressed base. (Weeks et al, 2005) This tree can develop three distinct habits including the vase-shaped form in which the trunk divides into several erect limbs strongly arched above and terminating in numerous slender, pendulous branchlets. A more wide-spreading and less arching form occurs, as well as a narrow form with branchlets clothing the entire trunk. This is a large, handsome, graceful tree, often with enlarged buttresses at base. (NPIN, 2008)

Flowers are green. (USDA PLANTS, 2009) Flowers are borne in axils on the old twigs. Calyx is bell-shaped and 4-9-lobed. Flowers hang on long drooping pedicels. (Peattie, 1930) Flowers bloom in clusters along the stem. (Hultman, 1978) They have no petals. (Weeks et al, 2005) Bloom color is red or green. (NPIN, 2008) Flowers are born on a shallowly lobed calyx. They are slightly asymmetric, with 7-9 lobes and ciliate margins. There are 7-9 stamens. Anthers are red and stigmas are white-ciliate and deeply divided. (FNA, 2006)

Fruit is brown. (USDA PLANTS, 2009) The samara (winged fruit) is rounded, the wing continuous all around except at the apex. Fruit may be oval or ovate, and is ciliate with fine hairs on the margins. (Peattie, 1930) Single seeds are each surrounded by a papery wing. (Hultman, 1978) Fruit is round and flat with hairy margins. The tip is deeply notched. (Weeks et al, 2005) The fruit is a yellowish to cream samara with narrow wings and hairy edges. Seeds are thick but not inflated. (UW, 2009) Samaras are yellow-cream when mature, though sometimes tinged with reddish purple (particularly in the Southern range of species). They are arrowly winged, with ciliate margins. Cilia are yellow to white. (FNA, 2006)

Leaves are green and coarse. (USDA PLANTS, 2009) Leaves are obovate-oblong and abruptly pointed. Leaves are oval, unequal-sided at the base, and sharply doubly serrate. They are rough above, dull green, and paler below. (Peattie, 1930) Elliptical with a coarsely double-toothed edge, and tapering to a point. (Hultman, 1978) Simple leaves that have a lop-sided base. Fall coloration is yellow. (Weeks et al, 2005) Dark-green leaves have variable fall color. (NPIN, 2008)

Stems This tree has a single stem growth habit. (USDA PLANTS, 2009) Erect arching branches form an umbrella-shaped crown. Twigs and buds are smooth or sparingly pubescent. (Peattie, 1930) Alternate branching is typical. Buds are elongate with chestnut-brown, slightly hairy scales. Twigs zig-zag from node to node. Lateral leaf buds lie against the twig. (Weeks et al, 2005) usually forked into many spreading branches, drooping at ends, forming a very broad, rounded, flat-topped or vaselike crown, often wider than high. (UW, 2009) Old-growth branches are smooth and not winged. Twigs are brown and pubescent to glabrous. (FNA, 2006)

Bark is flaky and gray. (Peattie, 1930) Bark is gray and tough. (Hultman, 1978) Bark is spongy until mature, and is tannish gray with thick, interlacing ridges. Inner bark is two-toned with light and dark layers. It is tan colored and spongy when young. (Weeks et al, 2005)

Tree height at 20 years is a maximum of 50' tall, at maturity 120.0' tall. (USDA PLANTS, 2009) Tree may be 50-100' tall. (Hultman, 1978) The tree was once 100'+ regularly, but is now more commonly 30-40'. (Weeks et al, 2005) It usually grows 60-80'. (NPIN, 2008)

Flowers inflorescence is less than 1" hanging cluster. (UW, 2009) Fascicles are less than 2.5 cm and the pedicel is 1-2 cm. (FNA, 2006)

Fruit is ovate and roughly 1 cm. Cilia to 1 mm. (FNA, 2006)

Leaves 4-6" long. (Hultman, 1978) Petiole is roughly 5 mm. Leaves are 7-14 × 3-7 cm. (FNA, 2006)

The tree can be harvested commercially for lumber products, naval store products, and pulpwood products. (USDA PLANTS, 2009) A valuable timber tree much planted for ornament though generally not the best to stand the fumes of some cities. Its branches meet across the road in a vaulted arch that permits the passage of high vehicles. (Peattie, 1930) It was used for years as an ornamental, and was once the most common shade tree in America. Recently it has been decimated by Dutch Elm Disease. (Hultman, 1978) Research is underway to produce disease-resistant cultivars for reintroduction in landscaping uses. (Weeks et al, 2005) This well-known, once abundant species, was familiar on lawns and city streets throughout America. The wood is used for containers, furniture, and paneling. Because of its fundamental architectural form, this is an ideal street tree. Because it is relatively odourless, the wood was used to make crates and barrels for cheeses, fruits and vegetables. (NPIN, 2008) Ulmus americana is the state tree for Massachusetts and for North Dakota. (FNA, 2006)

Various preparations of bark were used by pregnant women to insure stability of children, for menstrual cramps, for colds, for severe coughs, for dysentery, for "summer disease-vomiting, diarrhea and cramps," to facilitate childbirth and for parturition, for broken bones, for appendicitis, for sore eyes as an eye lotion, for gonorrhea, and for pulmonary hemorrhage. An infusion of root bark was taken for excessive menstruation. Wood was used in various capacities as a structural and vessel building material. (UM, 2009)