BIRCH FAMILY 



oval, rounded and enclose the unexpanded leaf. Petioles short, 

 scaly, dotted. 



Flowers. March, April, before the leaves. Monoecious. The 

 staminate aments are slender, cylindrical ; formed in the pre- 

 vious autumn, and hang stiff, in terminal clusters of three, four 

 or five together on short leafless branches or peduncles. When 

 mature they become drooping tassels loaded with pollen. They 

 consist of a central axis, which bears brown or purple, heart- 

 shaped or rhomboidal scales on short stalks. Beneath each scale 

 are three smaller ones, each containing a three to five-lobed 

 calyx-cup, with three to five stamens from whose anthers issues a 

 cloud of pollen. The pistillate aments are also formed during 

 the previous autumn ; are one-fourth to three-eighths of an inch 

 long, clustered usually in threes ; when mature they become deep 

 purple bristling with scarlet styles. The pistillate aments look 

 forward and downward. 



Fruit. Strobile of woody scales grown together, composed of 

 the pistillate ament enlarged and hardened. Its scales have be- 

 come woody, and each protects a wingless seed-vessel which is 

 one-celled and one-seeded. October. 



The two Alders, Alnus incana and Alnus rugosa, are 

 very much alike in habit; they enter upon the heritage 

 of the spring-time like two Dromios, not one before 

 the other. The change that the first warm days in 

 early spring produce in the Alder bushes is very grati- 

 fying to one who is listening for the call of the robin 

 and the song of the bluebird. It gives an added ap- 

 preciation of the power of sunshine. 



Through all the black days of winter, assailed by ice 

 and snow and cutting winds, the stiff, ungainly catkins 

 have held their place untouched and unchanged ; but 

 when " The hounds of spring are on winter's traces," 

 and the March sun has warmed the earth a little, the 

 dark, stiff cylinders begin to soften and lengthen, 

 gradually they lose the purple and take on the yellow, 

 the color of many stamens and much pollen. The su- 



466 



