BETULACEAE 67 



Key to the Alder Species 



Leaves conspicuously doubly serrate, the teeth sharp and rather 



coarse, the under surface glaucous; mature cones pendant; 



nutlets with a narrow, thick, marginal wing A. incana 



Leaves not conspicuously doubly serrate, the teeth small and 



rather blunt, the under surface green; mature cones erect; 



nutlets without a marginal wing A. rugosa 



ALNUS INCANA (Linnaeus) Moench 

 Speckled Alder 



The Speckled Alder, fig. 10, is a low, stooling shrub with 

 gray-dotted, reddish-barked stems that rise, at an angle of 20 

 to 40 degrees from the vertical, to a height of 8 to 10 feet. The 

 broadly ovate leaves, 2 to 4\6 inches long and nearly as wide, 

 are at first pubescent on both surfaces but become glabrate above 

 with age and eventually nearly glabrous and distinctly glaucous 

 beneath. The leaf tip is acute or shortly acuminate, the base 

 broadly rounded or subcordate and often a little asymmetrical. 

 The margins are doubly and sharply serrate, and the veins, 

 beneath, are prominent, parallel, and pinnately arranged so as 

 to terminate in the tips of the large teeth. The twigs are pu- 

 bescent and grayish at first but become smooth and turn to 

 golden or reddish brown marked by many dark specks. They 

 are terete to slightly triangular, contain small, continuous 3-sided 

 pith and bear rather large, 3-scaled, ovate, puberulent, stalked, 

 gummy, red-brown buds ]4. inch long, w^hich are set singly above 

 somewhat raised, half-round leaf-scars dotted with 3 bundle 

 traces and flanked by narrow, inconspicuous stipule scars. The 

 early deciduous stipules are conspicuous, foliaceous, lanceolate, 

 entire, pubescent, and about i/^ inch long. 



The slender staminate catkins occur in groups of 3 or more. 

 Each is 2i/4 to 3 inches long when in flower and stands on a 

 peduncle yi to }^ inch long. The pistillate catkins occur in 

 clusters of 2 to 7 near the end of branchlets. They are oval, 

 about i/i inch long by ^ inch wide in flower but become woody 

 and looser in fruit. The minute, reddish-brown to chestnut- 

 colored nutlets are ovoid and flat, and the edge of the shell 

 extends outward slightly into a narrow, thick margin or wing. 



DiSTRiBUTiox. — The Speckled Alder grows in cold swamps 

 and on low ground along streams from Newfoundland south- 

 ward into New York and westward into Saskatchewan and 



