ULMACEAE 



American Elm. White Elm 



Ulmus americana L. 



HABIT. A handsome tree 75-100 feet high and 3-6 feet in 

 diameter (max. 120 by 10 feet); open grown trees commonly 

 dividing near the ground into several ascending limbs forming 

 a vase-shaped crown; perhaps our most common ornamental 

 species. 



LEAVES. Oblong-obovate to oval; 4—6 inches long; coarsely 

 doubly serrate; thick and firm; base conspicuously oblique; 

 dark green and more or less rough above; paler below. 



FRUIT. A smooth, oval to ovate samara Yi inch long, ciliate 

 on margins and deeply notched at apex; seed cavity distinct; 

 in long-stalked fasiccles; maturing in late spring. 



TWIGS. Slender; round; red-brown; hairy at first becoming 

 glabrous. Winter buds: lateral H inch long, chestnut-brown, 

 acute. 



BARK. Thick; ash-gray; variable, but typically diamond- 

 shaped by furrows; alternate light and dark layers in outer 

 bark. 



WOOD. The most important of the elms. 



SILVICAL CHARACTERS. Moderately tolerant; shallow- 

 rooted; typical of moist sites, but hardy and widely planted 

 on dry shclterbelts ; seriously threatened by Dutch Elm disease; 

 with mixed hardwoods. 



Three unimportant elms are found in the Southeast; all of 

 these are characterized by having corky wings on the twigs and 

 small leaves. They are distinguished in the key. 



1. Winged elm, Ulmus alata Michx., flowers and fruits in the spring; 

 it is characterized by doubly serrate leaves 1-2J^ inches long and 

 hair-covered fruit Vz inch long with a distinct seed cavity. 



2. Cedar elm, Ulmus crassifolia Nutt., flowers and fruits in the fall; it 

 is characterized by nearly singly-toothed leaves 1-2!^ inches long 

 with rounded to acute apex and hair-covered fruit V-i-Vi inch 

 long with a distinct seed cavity. 



3. September elm, Ulmus serotina Sarg., flowers and fruits in the fall; 

 it is characterized by acuminate leaves 2-4 inches long and fruit 

 ciliate with white hairs. 



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