4l7P THE CATKIN PAMILT. 



1. Common Alder. Alnus glutinosus, Linn. 



{Betiila Alnus, Eng. Bot. t. 1508.) 



A moderate-sized tree, of a dark hue. Leaves stalked, broadly ovate or 

 orbicular, sharply toothed, aud occasionally lobed, glabrous, or with a Uttle 

 down in the axUs of the veins on the under side. Catkins 2 or 3 together, 

 in terminal clusters or small panicles ; the males long, loose, and drooping ; 

 the females not half an inch long, with the styles slightly protruding. In 

 the fruiting catkin the scales are not unlike those of a miniature fir-cone. 



In wet woods, and borders of streams, and wet pastures, in Europe and 

 western Asia, not extending to the Arctic Circle. Abundant in Britain. 

 Fl. early spring, before the leaves are fully out, the catkins having been 

 formed the previous autumn, 



III. BIRCH. BETULA. 



Flowers moncecious, the males in cylindrical catkins, usually pendulous, 

 with broad, shortly stalked scales. Stamens 8 to 12 under each scale, the 

 anthers on vei-y short filaments, the cells distinct, some with a small scale 

 xmdemeath, and all irregularly ari'anged in 3 flowers. Female catkins 

 cylindrical and compact, each with 2 small scales mside, and 3, rarely more 

 flowers. No perianth. Ovary flat, with 2 styles and 2 cells, with a pen- 

 dulous ovule in each. In the fruiting catkin the scales (formed of the cat- 

 kin-scale, with the 2 inner ones combined) are somewhat enlarged, and 

 3-lobed, falling ofi" wdth the nuts, which are small and seed-like, flat, sur- 

 rounded by a scarious wing. 



A small genus, confined to the northern hemisphere, and not reaching 

 the tropics. 



Tree, with broadly ovate, usually pointed I^avoa , • 1. Common B, 



Shrub, with small, orbicular leaves 2. Dtoca^B, 



1. Common BircH. Betula alba, Linn. 

 (Eng. Bot. t. 2197. JB. glutinosa, Bab. Man.) 



An elegant tree, with slender, often gracefully drooping branches, the 

 white bark of the trunk readily peehng off in layers. Leaves usually broadly 

 ovate, taper-pointed, and toothed, but varying from rhomboidal to triangular 

 or broadly cordate, often trembling on their slender stalks like those of the 

 Aspen, glabrous and shining, with minute glandular dots when young. Male 

 catkins drooping, 1 to 2 inches long ; the females shortly stalked, about 

 6 lines long when in flower. Fruiting catkins 1 to li inches, the scales wedge- 

 shaped, full 2 lines long, broadly 3-lobed. 



In woods, in northern and central Europe, Russian Asia, and North Ame- 

 rica, more limited to mountain districts in southern Europe. Extends all 

 over Britain. Fl. spring, before the leaves are fully out. 



2. D'warf Birch. Betula nana, Linn. 

 (Eng. Bot. t. 2326.) 

 Usually a small shrub, but when left to itself will form a tree of 20 feet. 

 Leaves very shortly stalked, nearly orbicular, seldom above half an inch 

 long, and not pointed. Catkins small and sessile, the males oblong or 

 shortly cylindrical, the females scarcely above 3 hues long. Fruiting cat- 

 kins about 6 lines long, the scales not so thin, nor falling off so readily as 

 in the common -B. 



