64 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 51 



"haw." It contains one to five hard, bony-shelled nutlets. Each 

 nutlet contains a single brown seed. 



Hawthorns are shrubby-looking trees with spiny, stout, 

 coarse, ascending or spreading branches and broad, open heads. 

 The short trunks are covered with dark, scaly bark. Although 

 over 100 species have been recorded for Illinois, only a very few 

 are well known. Red haw (Crataegus mollis), one of the larger 

 hawthorns, is common in many woodlands in the state. Wash- 

 ington thorn (C. phaenopijrum) , coekspur thorn (C. crus-galli) , 

 and English hawthorn (C. monogyna) represent the more com- 

 mon hawthorns grown for ornamental purposes. They are excel- 

 lent for landscaping around one-story buildings. They grow to a 

 height of 15-40 feet with a branch spread of 15-25 feet. How- 

 ever, they may be severely damaged by fire blight or by cedar 

 rusts. They are seldom injured by ice and wind. The hard wood 

 of hawthorn is tough and is used for tool handles, fishing rods, 

 mallets, and other small articles. 



Hickory 



Hickory is a moderate to large forest tree confined to the 

 eastern part of the North American continent. Of the 15 species 

 which occur in the United States, only 8 are native to Illinois 

 and only 4 of these 8 are suggested for use as occasional speci- 

 men trees in ornamental plantings. These are shellbark or shag- 

 bark (Carya ovata) , big shellbark or kingnut (C laciniosa) , 

 bitternut or pignut (C cordiformis) , and mockernut or white 

 hickory (C tomentosa) . 



Shellbark hickory (Fig. 63), with its narrow crown and 

 long, stout, ascending branches, grows to a height of 80-90 feet, 

 with a branch spread of 25-30 feet. It is common throughout 

 Illinois and grows on deep, rich soil on low hills, along streams, 

 and near swamps. It prefers an acid soil. The 8- to 14-inch-long, 

 alternate, compound leaves (Fig. 63 inset) are made up of five 

 to seven finely toothed leaflets. The thin but firm, sharp-pointed, 

 elliptical leaflets are 5-7 inches long and 2-3 inches across. They 

 are smooth and dark green above, pale and often hairy beneath, 

 and become rusty-golden-yellow in autumn. Male and female 

 flowers are produced separately on the same tree. Male flowers 

 develop as 4- to 6-inch-long catkins in groups of three. Female 

 flowers develop as two- to five-flowered spikes on the tips of 

 new twigs. The hard-shelled, four-ribbed, nearly globose nut 



