68 BETULACEAE 



Nebraska. In Illinois, which lies on the southern boundary of 

 its range, it is to be found only on the moorland north of 

 Waukegan, in Lake County, where it is rare. 



ALNUS RUGOSA (Du Roi) Sprengel 



Hazel Alder 



The Hazel Alder, fig. 10, is an erect shrub, usually 12 or 14 

 feet high but often in its larger growth somewhat treelike, 

 with flexuous, ascending branches and distinctly obovate leaves, 

 2l/2 to 4 inches long and about two-thirds as wide, which are 

 dark green above and lighter green, glutinous, and often shiny 

 beneath. They are pubescent on both surfaces when young but 

 become glabrate in age. The veins beneath remain, however, 

 distinctly brown and hairy. The margins are finely toothed 

 with minute, divergent, bluntly pointed teeth, each of which 

 forms the end of 1 small veinlet. The leaf apex is rounded, 

 with at times a small point, and the base slopes in a w^edge 

 shape to the petiole, which is of moderate size, pubescent, and 

 yz to ^ inch long. The stipules are quickly deciduous. The 

 main branches and trunk are fluted, or angled, and covered with 

 thin, nearly smooth, gray or, on younger growth, reddish to 

 brown bark. The twugs are slender, straight, fluted or angled, 

 dark reddish brown on all but the newest growth, and glabrous, 

 but new growth is pubescent with brown hair. The blunt, 

 pubescent, narrowly ovate, brown buds, about j/g inch long, are 

 raised on stout stalks nearly as long as the buds. The leaf-scars 

 are small, little or distinctly raised, narrowly to broadly oval, 

 and marked with 3 distinct bundle traces. 



Staminate catkins are borne at the end of new grow^th. They 

 are pendulous, stout, and l],^ to 5 inches long in flower. The 

 pistillate catkins, formed the previous fall, are globular to ovate 

 in shape, w^oody, conelike, ^ to ^ inch long, and stand erect 

 on the end of branches in clusters of 2 to 5. 



Distribution. — The Hazel Alder ranges throughout most of 

 the eastern half of the United States, from Maine to Florida 

 and west to Minnesota and Texas, preferring throughout this 

 territory the margins of streams, wet woods, and cold swamps. 

 Its general distribution, however, is patchy, and large territories 

 apparently are avoided. In Illinois, it occurs in practically all 

 parts of the state, though it is more common northward. 



