ORDER 120. BETULACEJE. 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 flavor. Leaves 3 4,' long, about as wide. Sterile aments 2 3' 

 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. rhombic-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 tree 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. May. (B. rubra MX.) 



4 B. populifolia Ait. POPLAR-LEAVED BIRCH. WHITE BIRCH. (Fig. 106.) Lvs. 

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

 smooth petioles ; fertile aments pedunculate ; scales with roundish, lateral lobes. 

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

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

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

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



5 B. papyracea Ait PAPER BIRCH. CANOE BIRCH. Lvs. ovate, acuminate, 

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

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

 woods of N. Eng. to Wis. and Can. It sometimes attains the height of 60 7 Of, 

 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 2 3' long, 

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

 easily wrought May, Jn. > 



jd 1 . MINOR. Lvs. smaller, ovate, glabrous, acute, some of them roundish-obtuse. 

 White Mts. Shrubs 6 9f high. 



6 B. pumila 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 the leaves ; scales half 3-cleft, lobes ovate- 

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

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

 to Hudson's Bay. Height 2 to Gf. Lvs. about 9'' by 6 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, crenate, 

 reticulated beneath; scales of the $ ament deeply 3-parted; seeds orbicular, nearly 

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

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

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

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

 iana Tuckerman.) 



3. AL'NUS, Tourn. ALDER. (The ancient Latin name from Celtic 

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

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

 i? -celled. ? Aments ovoid, bracts cuncatc, truncate, fleshy, 2-flowerecl ; 

 ^alyx of 4 scales adnate below to the bracts, all persistent and woody 

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

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

 $ Aments panicled. (Fig. 111.) 



Fruit -wingless, !Nos. L 2. . Fruit broadly winsrcd. (AJ.NASTKK, Spach.) Xo. 3. 



1 A. incana Willd. SPECKLED ALDER. BLACK ALDER. Lvs. submembranou*. 

 oblong, acutish, obtuse at bate cr cordate, margin somewhat lobed, sharply ser- 

 rate, glaucous-pubescent bt.-itath; veins hirsute, their^ axils naked; stip. oblong- 



