BETDLACKE. (BIROa FAMILTv) 411, 



leaves often spicy-aromatic. Foliage mostly ttiiji and Ught. Buds sessile, scaly 

 Steiile catkins long and drooping, terminal and lateral, formed in summer, re- 

 maining naked through the succeeding winter, and expanding their golden 

 flowers in early spring, preceding the leaves : fertile catkins oblong or cylindri- 

 cal, lateral, protected by scales through the winter, and developed with the 

 leaves. (The ancient Latin name.) 



* 7'rees, with the bark of the trunk white externally, separable in thin sheets : petioles 



dender : fertile catkins cylindrical, pedimcled, spreading or drooping. 



1. B. AUm, var. popnlifdlia, Spach. (AuEBiOAir White BiBca.) 

 Leaves triangular (deltoid), very taper-pointed, truncate or nearly so at the broad 

 base, smooth and shining both sides (glandular-dotted when young). (B. popnli- 

 folia, Ait, ) — Common on poor soils, Penn. to Maine, near the coast. — A small 

 and slender, very graceful tree, with chalky-white bark, much less separable 

 into sheets than the next species ; the very long-pointed leaves on petioles of 

 fully half their length, tremulous as those of an Aspen. (Eu.) 



2. B. papyracea, Ait. (Faf&k Birch. Canob Birch.) Leaues 

 ovate, taper-pointed, heart-shaped or abrupt (or rarely wedge-shaped) at the base, 

 smooth above, dull underneath ; lateral lobes of the fruit-bearing bracts short and 

 rounded. — Woods, New England to Wisconsin, almost entirely northward, and 

 extending far north. — A large tree, with fine-grained wood, and very tough 

 durable bark splitting into paper-like layers. Leaves dark-green above, pale, 

 glandular-dotted, and a little hairy on the veins underneath, sharply and une- 

 qually doubly serrate, 3-4 times the length of the petiole. There is a dwarf 

 mountain variety. 



* ♦ Trees, with reddish-brown or yelknmsh bark : petioles short : fertile catkins ovoid- 



oblong, scarcely peduncled. 



3. B. nlgra^ L. (Biveb or Bed Birch.) Leaves rhombic-ovate, acutish 

 tit 6otA e)t<&, whitish and (until old) downy underneath; fertile catkins oblong, 

 somewhat peduncled, woolly ; the bracts with oblong-linear nearly equal lobes. 

 (B. rubra, Michx. f.) — Low river-banks, Massachusetts to Virginia and south- 

 ward. — A rather large tree, with reddish-brown bark and compact light-colored 

 wood : leaves somewhat Alder-like, glandular-dotted, sharply doubly serrate. 



4. B. excelsa, Ait. (Yellow BIrch.) Leaves ovate or eilipticai, point- 

 ed, narrowed (but mostly heart-shaped) at the base, smoothish, unequally senate 

 with coarse and very sharp teeth ; fruiting catkins ovoid-oblong, slightly hairy ; lobes 

 of the scales nearly equal, acute, slightly diverging. — Moist woods, New England 

 to Lake Superior, and northward. — Tree 40° -60° high, with yellowish silvery 

 bark, thin leaves : twigs less aromatic than in the next ; the wood less valuable. 



5. B. lenta, L. (Cherry Birch. Sweet or Black Birch.) Leaves 

 heart-ovate, pointed, sharply and finely doubly seiTate, hairy on the veins beneath ; 

 fruiting catkins elliptical, thick, somewhat hairy ; lobes of the veiny scales nearly 

 equal, obtuse, diverging. — Moist rich woods. New England to Ohio and north- 

 wai-d, and southward in the mountains. — A rather large tree, with dark chcst- 

 nnt-brown bark, reddish bronze-colored on the sptaj, much like that of the 

 Garden Cherry, which the leaves also somewhat resemble ; the twigs and foliaga 

 spicy-aromatic : timber rose-colored, fine-grained, valuable for cabinet- work. 



