Winged Elm
Ulmus alata
Elm family (Ulmaceae)

Description: This small to medium-sized tree is 15-60' tall, consisting of a relatively short trunk and narrow to rounded crown. Trunk bark is grayish brown to gray and somewhat rough; it is defined by flat ridges and irregular fissures. The bark of branches and older twigs are gray and more smooth, although twigs usually have pairs of corky wings that are up to " long with irregular outer margins. These winged twigs are often crooked. Young twigs are brown, smooth, and glabrous, while young shoots are light green and pubescent. Alternate leaves occur in two ranks along the young twigs and shoots. These leaves are 1-3" long and -1" across; they are lanceolate-oblong, oblanceolate-oblong, or elliptic-oblong in shape, while their margins are doubly serrate. Leaf bases are narrowly rounded and slightly asymmetric, while leaf tips are acute. Leaf venation is pinnate with numerous lateral veins that are straight and sometimes forked toward their tips. The upper leaf surface is medium to dark green and glabrous to slightly rough-textured (scabrous), while the lower leaf surface is pale green and pubescent (especially along the veins). The petioles are very short (about 3 mm. or 1/8" in length), light green, and pubescent.

The flowers of Winged Elm (Ulmus alata) are perfect and about 6 mm. (") in length, consisting of a light green calyx with 5 rounded lobes (but sometimes up to 9 lobes), 5 stamens with reddish anthers (but sometimes up to 9 stamens), and a flattened green ovary with a pair of stigmata. These flowers are produced from short spur twigs in small clusters up to 1" long; there are 4-10 flowers per cluster. The pedicels of the flowers are slender. The blooming period occurs from late winter to early spring for 1-2 weeks before the vernal leaves develop. Afterwards, these flowers are replaced by flattened samaras that become mature during mid-spring before the vernal leaves fully develop. Mature samaras are about 7-10 mm. long and about one-half as much across; they are typically reddish brown with pubescent sides and strongly ciliate margins. At the tip of each samara, there is a pair of narrow curved claws. Each samara contains a single small nutlet in its center. The samaras are dispersed by the wind.

This tree prefers full to partial sun and moist to dry conditions. Different kinds of soil are tolerated, including those that contain, loam, clay, sand, or rocky material. The fertility of the soil and moisture regime have a strong impact on the ultimate size of this tree. It is hardy to at least Zone 6. Like other native elms, it has some vulnerability to Dutch Elm disease.

Range & Habitat: The native Winged Elm is fairly common in southern Illinois, while in the rest of the state it is absent (see Distribution Map). Typical habitats include rocky upland woodlands, upland savannas, bluffs, sandstone and limestone glades, abandoned fields, and fence rows. Less often, this tree occurs in moist rocky ravines and canyons. This is a pioneer species of difficult marginal habitats, woodlands that have been subjected to fire, and more developed areas with a history of disturbance.

Faunal Associations:
Numerous insects feed on the foliage, wood, or plant juices of Winged Elm (Ulmus alata) and other elms (Ulmus spp.). These species include larvae of the Elm Borer (Saperda tridentata) and other wood-boring beetles, the Elm Leaf Beetle (Xanthogaleruca lutea) and other leaf beetles, the Elm Leaf Aphid (Tinocallis ulmifolii) and other aphids, many leafhoppers (Eratoneura spp., Erythridula spp.), Heidemann's Plant Bug (Lopidea heidemanni), the Giant Walkingstick (Megaphasma denticrus), larvae of the Elm Sawfly (Cimbex americana), caterpillars of the Question Mark (Polygonia interrogationis) and other butterflies, and caterpillars of Ceratomia amyntor (Elm Sphinx) and other moths. The Insect Table lists many of the non-lepidopteran insect-feeders, while the Moth Table lists many of the moth (and some butterfly) species. These insects often attract insectivorous songbirds. White-Tailed Deer occasionally feed on the young leaves and twigs during the spring, while the nutlets of the samaras are eaten by the Fox Squirrel, Gray Squirrel, Red Squirrel, and Eastern Chipmunk. Many upland gamebirds and various songbirds also feed on the nutlets or buds of elms; these species include the Prairie Chicken, Wild Turkey, Carolina Chickadee, Eastern Goldfinch, Rose-Breasted Grosbeak, Yellow-Rumped Warbler, and extinct Passenger Pigeon. In southern Illinois, the Prairie Warbler sometimes builds nests in saplings of Winged Elm in shrubby open areas.

Photographic Location:
A parking and picnic area within an upland woodlands in southern Illinois.

Comments: Winged Elm (Ulmus alata) has a distinctive appearance because of its corky-winged twigs and small branches. The only other native elm in Illinois with this characteristic is the Rock Elm (Ulmus thomasii), which is found in the northern half of Illinois. This latter elm can be distinguished from the former tree by its larger leaves and longer petioles. The wood of Winged Elm is relatively heavy, fine-grained, light brown, and difficult to split. However, it is not particularly strong. Such items as furniture, hardwood flooring, boxes, wooden crates, tool handles, and high quality hockey sticks have been made from it. Various fungi feed on the wood of elms (Ulmus spp.), particularly rotting logs, trunks, and stumps. These fungal species include Auricularia mesenterica (Tripe Fungus), Coprinellus micaceus (Glistening Inkcap), Hypsizygus ulmarius (Elm Leech), Pluteus aurantiorugosus (Flame Shield), Rhodotus palmatus (Wrinkled Peach), Rigidoporus ulmarius (Giant Elm Bracket), and Flammulina veluptipes (Velvet Shank). This last fungus is the source of the cultivated "enoki" mushrooms that are sold in supermarkets.