Ulmus alata

Ulmus alata, the winged elm or wahoo, is a small- to medium-sized deciduous tree endemic to the woodlands of the southeastern and south-central United States. The species is tolerant of a wide range of soils, and of ponding, but is the least shade-tolerant of the North American elms. Its growth rate is often very slow, the trunk increasing in diameter by less than

5 mm (3/16 in) per year. It is sometimes considered a nuisance because it invades old fields, forest clearings, rangelands and other areas. This makes it difficult to eradicate with herbicides.

Description

As its common and scientific names imply, winged elm is most easily recognized by the very broad, thin pair of corky wings that form along the branchlets after a couple of years. The average tree grows to 13 m in height and 13 m in breadth (43 ft. x 43 ft.). However, on rich alluvial soils like those found in the Mississippi River Delta, some specimens can reach twice that height. (See “Notable trees” below). The crown can be either rounded or pyramidal; the branches are pendulous. The leaves are comparatively small for the genus, less than 6.5 cm (2+1/2 in) long and less than 2.0 cm (3/4 in) broad, oblong-lanceolate to narrowly elliptic, thin in texture, and smooth above with serrate or doubly serrate margins. The leaves turn bright yellow in Autumn. In Autumn, the perfect apetalous wind-pollinated flowers turn bright yellow. The reddish samaras are also relatively small, less than 8 mm (5/16 in) long, narrowly elliptic with two long incurving stigmas at the tip, and usually disperse before the end of April.

Cultivation

Ulmus alata is rarely cultivated beyond its natural range. It remains in commercial production in the US, and is occasionally available in Europe. At the beginning of the 19th century, the tree was one of the three American elm species cultivated in ornamental plantations in Britain, but is now rare there. Several specimens are grown in New Zealand.