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. The tree is occasionally considered a nuisance as it readily invades old fields, forest clearings, and rangelands, proving particularly difficult to eradicate with herbicides.