ULMACEAE 33 



clustered flowers appearing before the foliage; and round 

 samaras. 



1. Leaves only once-serrate, scarcely 5 cm. long. 2. 

 Leaves doubly serrate. 3. 



2. Flowering in early spring. U. pumila. 

 Flowering in summer or autumn. U. parvifolia. 



3. Buds light brown: fruit ciliate. 4. 



Buds red-brown or nearly black: not deliquescent. 8. 



4. Percurrent, often corky-winged. 5. 

 Deliquescent, without corky wings or ridges. 6. 



5. Cork-wings thin. (Wahoo). U. alata. 

 Cork-ridges thick. (Rock elm.). U. racemosa. 



6. Shrub. U. americana nana. 

 Trees. 7. 



7. Leaves green. (White elm). U. americana. 

 Leaves yellow. (Golden elm). U. americana aurea. 



8. Buds and fruit glabrous. 9. 

 Buds pubescent. 11. 



9. Leaves large (8-12 cm. long). (Dutch elm). XU. hollandica. 

 Leaves mostly 5-8 cm. long. 10. 



10. Twigs not corky-ridged. X U. foliacea. 

 Twigs often with corky outgrowths. U. foliacea suberosa. 



11. Twigs bristly: buds red-hairy. (Slippery elm). U. fulva. 

 Twigs and buds soft-hairy: fruit glabrous. 12. 



12. Some leaves shouldered or 3-pointed. 13. 

 Leaves not shouldered. (English elm). 15. 



13. Leaves green. 14. 



Leaves purple. U. glabra atropurpurea. 



14. Not weeping. (Scotch elm). U. glabra. 

 Weeping. (Camperdown elm). U. glabra camperdownii. 



15. Leaves not variegated. U. campestris 

 Leaves variegated. 16. 



16. Leaves white, green-blotched. var. argenteo-maculata. 

 Leaves green, white-blotched. var. argenteo-marmorata. 



PLANER A. Planer Tree. 

 Deciduous small trees with somewhat brownish wood with 



