ULMACEAE 



Slippery Elm 



Ulmus rubra Muhl. {Ulmus fulva Michx.) 



HABIT. A medium-sized tree 40-70 feet high and 1-2 feet 

 in diameter (max. 5 feet); clear trunk; rounded, open crown 

 with spreading branches and ascending twigs. 



LEAVES Oblong-obovate to oval; 4-7 inches long; coarsely 

 doubly serrate; thick and firm; base conspicuously oblique; 

 dark green and rough above; paler and rough below. 



FRUIT. A suborbicular samara about % inch long; seed 

 cavity distinct, brown-woolly; wings and margins smooth; apex 

 entire or nearly so; in short-stalked fascicles; maturing in spring. 



TWIGS. Rather stout; ash-gray; rough. Winter buds: lateral 

 V4 inch long, nearly black, hairy. 



BARK. Thick; dark red-brown; nearly parallel furrows; 

 without alternate light and dark layers; inner bark mucilag- 

 inous. 



SILVICAL CHARACTERS. Moderately tolerant; wide 

 lateral roots; with mixed hardwoods; varied sites. 



* * * 



Rock Elm. Cork Elm 



Ulmus thomasii Sarg. ( Ulmus racemosa Thomas) 



HABIT. A handsome medium-sized tree 6(>-80 feet high 

 and 2-3 feet in diameter (max. 100 by 5Vi feet); trunk persisting 

 into crown; narrow crown with drooping lower branches. 



LEAVES. Obovate to oval; 2^-5 inches long; coarsely 

 doubly serrate; thick and firm; base nearly equal; dark green 

 and usually glabrous above; paler and slightly hairy below. 



FRUIT. An obovate to oval samara %.-! inch long, hairy 

 all over; seed cavity indistinct; apex shallowly notched; mar- 

 gins ciliate; in racemose cymes on long slender stalks; maturing 

 in spring. 



TWIGS. Rather stout; red-brown; usually developing corky 

 wings. Winter buds: lateral V4 inch long, brown, acute, downy- 

 ciliate. 



BARK. Thick; dark gray-brown; deeply and irregularly 

 furrowed; alternate light and dark layers in outer bark. 



SILVICAL CHARACTERS. Intermediate in tolerance; 

 wide lateral roots; with mixed hardwoods; varied sites; poor 

 reproduction. 



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