422 
BETULACEJE. (BIRCH FAMILY.) 
ful, but useless, tree, 20° - 40° high, with a chalky-white bark, much 
less separable into thin sheets than in No. 2; the poplar-shaped and 
very long-pointed leaves as tremulous as an Aspen, on petioles nearly 
half their length, serrate with small and very short teeth, and also 
coarsely toothed more or less. 
2. B. papyracea, Ait. (Paper Birch. Canoe Birch.) 
Leaves 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, N. England to 
Wisconsin, almost entirely northward. — 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 unequally doubly serrate, 
3-4 times the length of the petiole. There is a dwarf mountain var. 
* * Trees with reddish-brown or yellowish bark : petioles short: fertile 
catkins ovoid-oblong, scarcely peduncled. 
3. B. lligra, L. (River of~ Red Birch.) Leaves rhombic- 
ovate i, acutish at both ends , whitish and (until old) downy underneath ; 
fertile catkins oblong, somewhat peduncled, woolly j the bracts with 
oblong-linear nearly equal lobes. (B. rubra, Michx.f.) — Low river- 
banks, Massachusetts to Penn, eastward and southward.—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 ellip¬ 
tical, pointed, narrowed (but mostly heart-shaped) at the base, smooth- 
ioh, unequally serrate with coarse and very sharp teeth ; fruiting cat¬ 
kins ovoid-oblong , slightly hairy ; lobes of the scales nearly equal , avute, 
slightly diverging. — Moist woods, common northward. Tree 40 3- 
60° high, with yellowish silvery bark, thin leaves, and the twigs and 
foliage aromatic, but not so much so as in the next; the wood, also, 
not so valuable. 
o. B. lenta, L. (Cherry Birch. Sweet or Black Birch.) 
Leaves heart-ovate , pointed, sharply and finely doubly serrate, hairy 
on the veins beneath; fruiting catkins elliptical, thick, somewhat hairy ! 
lobes of the veiny scales nearly equal, obtuse, diverging . — Moist rich 
woods, very common northward. —A rather large tree, with dark 
chestnut-brown bark, reddish-bronze-colored on the spray, much lik« 
that of the Garden Cherry, which the leaves also somewhat resemble; 
the twigs and foliage spicy-aromatic : timber rose-colored, fine-gram* 
ed, valuable for cabinet-work. 
* * * Shrubs, with brownish bark and rounded crenate-toothed leaves ■ 
fertile catkins very short-peduncled. 
6. B« puiilila, L. (Low Birch.) Erect or ascending; leaves 
obovate or roundish-elliptical , coarsely crenate-toothed, those of the 
