Ulmus crassifolia Nutt., the Texas cedar elm or simply cedar elm, is a deciduous tree native to south-central North America, mainly in southern and eastern Texas, southern Oklahoma, Arkansas, and Louisiana, with small populations in western Mississippi, southwest Tennessee, and north-central Florida;[2] it also occurs in northeastern Mexico.
The wind-pollinated apetalous perfect flowers are produced in the late summer or early fall; they are small and inconspicuous, with a reddish-purple color, and hang on slender stalks a third to a half inch long.
The fruit is a small winged samara 8–10 mm long, downy on both surfaces at first, maturing quickly after the flowering in late fall.
[citation needed] Cedar elms are known to be highly immune to Texas root rot caused by the fungus Phymatotrichopsis omnivora.
Because of this, it is usually planted in regions where P. omnivora is prevalent, since the closely related lacebark elm is highly susceptible and easily killed by the fungus.