CODER 120. BETULACE^E. 649 



diameter of 2 to 3f. The trunk Is invested with a dark brown or reddish bark, 

 which becomes rough in old trees, and is remarkable for its agreeably aromatic 

 fragrance and navor. Leaves 3 4=' long, about \ as wide. Sterile aments 23' 

 long, fertile much shorter and thicker. In spring the cambium affords the boys a 

 delicious morsel Wood reddish, strong, compact. Apr., May. 



3 B. nigra Ait. RED BIRCH. Lvs. rhmnbic-ovate, acute at each end, doubly ser- 

 rate, or obscurely 9 to 13~lobed, glaucous beneath ; fertile ament sessile, erect, ovoid, 

 scales villous, the segments linear, equal. A treo 30 to 50f high, growing on 

 banks of streams and in river swamps, Mass,, 111. and Fla. (!) Trunk covered 

 with a reddish or chocolate-colored bark which at length becomes very loose and 

 torn, hanging in shreds, and finally rough like that of the black cherry. Branches 

 arched and slender ; branchlets almost filiform, often clothing the trunk to the 

 base. Lvs. dark green above, about 3' by 2' often smaller, petioles 6 to 8" long, 

 pubescent. Hay. (B. rubra MX.) 



4 B. populifolia Ait. POPLAR-LEAVED BIRCH. WHITE BIRCH. (Fig. 106.) Z.r.>-. 

 deltoid, long-acuminate, unequally serrate or obscurely many-lobed, very smooth, on 

 smooth p3tioles ; fertile aments pedunculate ; scales with roundish, lateral lobes, 

 Like the next, distinguished for the whito cuticle with which the trunk is in- 

 vested. It is common in tho rocky and mountainous woods of N. Eng., where it 

 seldom exceeds 30 to 40f in height. Tho branches are covered with a reddish- 

 brown bark, very slender, and throw out in May, long, pendulous aments. 



5 B. papyracea Ait. PAPER BIRCH. CAXOE BIRCH. Lvs. ovate, acumiriate, 

 doubly serrate, the veins hairy beneath; fertile aments nodding, pedunculate: 

 lateral lobes of the calyx short, roundish. This bircli is abundant in the hillside- 

 woods of N. Eng. to Wis. and Can. It sometimes attains tho height of GO 70t; 

 but is generally smaller. Trunk 1 2f diam., covered with a tough cuticle con- 

 sisting of numerous laminae, the outer of which is snow white. Of this the In- 

 dians construct their light canoes. Branches dark brown. Leaves 23' long,- -J 

 as wide. Sterile aments 1 2' long. The wood is of a fine, compact texture*, 

 easily wrought. May, Jn. 



fi. MINOR. Lvs. smaller, ovate, glabrous, acute, some of them roundish-obtuse. 

 White Mts. Shrubs G 9f high. 



6 B. piimila L. DWARF BIRCH. Shrub erect, its ascending branches glandular- 

 punctate, glabrous; Ivs. obovate, entire at base, obtusely serrate, glabrous; fertile 

 ament cylindrical, about as long as tho leaves ; scales half 3-cleft, lobes ovate- 

 oblong, middle one rather longest ; nut orbicular, conspicuously margined. A 

 beautiful shrub inhabiting tho mountainous districts of N. and N. W, States, N. 

 to Hudson's Bay. Height 2 to 6f. Lvs. about 0'' by G or 7", very regularly 

 toothed. Aments of both kinds 7 to 9'', (B. glandulosa MX.) 



7. B nana L, TINY BIRCH. Shrub, low, trailing, smooth ; Ivs. orbicular, craiofc, 

 reticulated beneath; scales of ilie ? ament deeply ^-parted; seeds orbicular, nearl<, 

 wingless. This miniature tree is found on tho summits of Mt, Clinton, Mt. Frank- 

 lin, &c., of the White Mts. It is scarcely more than a foot in height, often but si 

 few inches, the branches few and straggling, the Ivs. ^ to f diam., smooth both 

 sides pale and distinctly reticulate beneath, and on petioles 1 to 2" long, (B. Litti-1- 

 iano. Tuckerman.) 



3. AL'RUS, Tourn. ALDEK. (The ancient Latin name from Celtic 

 al, near, Ian, the river bank.) $ Aments cylindrie, drooping, the 

 bracts with 5 bractioles beneath ; calyx 4-partcd ; stamens 4, anthers 

 2-cellcd. ? Aments ovoid, bracts cuneate, truncate, fleshy, 2 -flowered; 

 calyx of 4 scales adnatc below to the bracts, all persistent and woody 

 in fruit ; fruit compressed, wingless or winged. Shrubs arising from 

 large and strong roots. Buds pedunculate, Lvs, plicate in vernation, 

 2 Aments paniclcd. (Fief. 111.) 



J Fruit tvingless, Nos, 1, 2. < Fruit broadly winged. (AI.NASTHK, Spncb.) No, " 



1 A. incana Willd. SPECKLED ALDER. BLACK ALDER, Lvs. submembranous, 

 oblong, acutish, obtuse at base cr cordate, margin wnnewhat lobed, sharply ser- 

 rate, glaucous-pubescent b^ncalfi / veins hirsute, their axils naked ; stip. oblony- 



