BIRCH FAMILY 



answers the same purpose that is served by the green 

 pulp of the leaf. As the shoot matures, the stomata 

 are succeeded by lenticels or spongy places, which 

 scattered over the external surface of the bark serve to 

 admit air to the interior of the stem. They appear at 

 first as roundish spots of very small size, but as the 

 shoot on which they occur increases in diameter the 

 lenticels enlarge. 



Gardeners think well of the Speckled Alder. It 

 thrives in wet places, its leaves push out early, making 

 it attractive when other shrubs are bare. Alders 

 transplant well, are natural adjuncts to a slow-flowing 

 stream, and appropriate companions for the willows. 



SMOOTH ALDER 



Alnus rugbsa. Ahnis semdata. 



The common alder of the southern states ; often found grow- 

 ing with the northern form, frequently forming thickets at the 

 edge of streams and in swamps ; usually six to twelve feet high. 

 Roots large, strong, throwing up many suckers ; bark astringent. 

 Ranges from Massachusetts to Florida, westward to southern 

 Minnesota and Texas. 



Stems. — When young, brownish green, smooth or downy ; 

 older stems grayish green or dark green. 



Leaves. — Alternate, simple, two and one-half to four and one- 

 half inches long, broad, oval or obovate, rounded or wedge- 

 shaped at base, minutely serrulate and undulate, rounded or 

 with a blunt point at apex. They come out of the bud pale 

 green and downy ; when full grown are thick, dark green, gla- 

 brous and shining above, paler green, and usually pubescent on 

 the veins beneath. Small, resinous dots appear on young leaves. 

 Midvein and primary veins depressed above, ridged beneath ; 

 downy when leaves are young, afterward downy at the axils only. 

 The autumnal tint is yellow touched with reel. Stipules broad- 



464. 



