ULMACEAE 69 



The European Alder, A. glutinosa (Linnaeus) Gaertner, has 

 escaped from cultivation in Du Page County. 



ULMACEAE 

 The Elm Family 



The elm family consists of trees and shrubs, which bear 

 simple, 2-ranked leaves that are asymmetrically oblique at the 

 base and monoecious, polygamous, or perfect greenish flowers 

 arranged in cymes or racemes. There are 3 to 8 sepals, which 

 are more or less united at the base, no petals, and there are 

 3 to 8 stamens opposite the sepals. The 2 pistils are united into 

 a 1- or 2-celled, superior ovary, which develops into a 1-seeded 

 samara, drupe or nut. 



The more than 150 species in this family, ascribed to about 

 15 genera, are widely distributed through the world, except in 

 the very far north and the very far south. In Illinois, the family 

 is well represented by elms and hackberries, but only 1 shrubby 

 species occurs in the state. 



CELTIS (Tournefort) Linnaeus 

 The Hackberries 



The hackberries are shrubs or trees with thin, smooth or 

 corky-ridged bark and usually serrate, 2-ranked, membranous 

 leaves that are oblique at the base. The axillary flowers are 

 monoecious, the staminate being either solitary or clustered and 

 the pistillate usually solitary. There are 4 or 5 deciduous sepals, 

 the same number of stamens, and a 1-celled ovary, which de- 

 velops into a globose or elliptic drupe containing a small amount 

 of pulp and a bony stone. 



There are about 60 species of hackberries widely distributed 

 in temperate regions in the northern hemisphere and in the 

 tropics. Besides two native tree species, the following shrubby 

 species occurs in Illinois. 



CELTIS PUMILA Pursh 



Shrubby Hackberry 



The Shrubby Hackberry, fig. 11, is usually a low shrub 5 or 6 

 feet tall, less frequently a small tree up to 12 feet tall, with thin, 



