BETULACEA. 
glandulosa, and Betula nana? are low shrubs. 
important, Betula alba,’ also ranging in several forms through Siberia to Japan. 
and eastern Massachusetts to Indiana and Minnesota, northward to 
Newfoundland, Labrador, Quebec, and Ontario, and westward in 
British America to the eastern foothills of the Rocky Mountains. 
1 Michaux, Fl. Bor.-Am. ii. 180 (1803). — Hooker, Fl. Bor.-Am. 
ii. 156. — Brewer & Watson, Bot. Cal. ii. 80.— Macoun, Cat. Can. 
Pl. 437. — Watson & Coulter, Gray’s Man. ed. 6, 472. 
Betula nana, Bigelow, Fl. Boston. ed. 2, 356 (not Linnzus) 
(1824). — Tuckerman, Am. Jour. Sci. xlv. 31. — Torrey, Fl. N. Y. 
ii. 101, t. 114. — Gray, Man. 423. 
Betula pumila, Hooker, I. c. (not Linnzus) (1839). 
Betula Littelliana, Tuckerman, J. c. 30 (18438). 
Betula glandulosa is a shrub with glabrous erect or prostrate 
stems from one to four feet long, glabrous obovate or orbicular 
leaves green on both surfaces, and short oblong or oval strobiles. 
It is distributed from Newfoundland and Labrador westward, by 
the shores of Hudson Bay to the valley of the Yukon River in 
Alaska, ranging southward to the alpine summits of the high moun- 
tains of New England and New York, to the northern shores of 
Lake Superior, the Rocky Mountains of Colorado, and the high 
Sierras of northern California. 
2 Linneus, Spec. 983 (1753). — Michaux, /. c. —Guimpel, Willde- 
now & Hayne, Abbdild. Deutsch. Holz. ii. 200, t. 148. — Hooker, 
l. c.—Smith & Sowerby, English Bot. xxxiii. t. 2326.— Hartig, 
Forst. Culturpfl. Deutschl. 333, t. 31. — Macoun, I. c. 
Betula nana is a semiprostrate shrub with slender eglandular 
pubescent or tomentose branchlets and glabrous minute subrotund 
or flabellate leaves (var. flabellifolia, Hooker [1. c.]), and glabrous 
oval strobiles half an inch in length; it is an inhabitant of all 
arctic and subarctic regions and of the alpine summits of the high 
mountains of central Europe. In America, where it grows in cold 
sphagnous swamps, it ranges from Newfoundland to Alaska. 
8 Linneus, l. c. 982 (1753). 
Of this widely distributed species, which is spread all over north- 
ern Europe and Asia, growing nearer to the Pole than any other 
tree of the Old World, and inhabiting swamps and gravelly plains at 
the north, and the mountain ranges of southern Europe and Asia 
Minor, two subspecies are now generally recognized. The Fra- 
grant Birch, — 
Betula alba odorata, Dippel, Handb. Laubholzk. ii. 172 (1892). 
Betula odorata, Bechstein, Diana, i. 74 (1815). — Reichenbach, 
Icon. Fl. German. xii. 2, t. 626. 
Betula glutinosa, Wallroth, Sched. Crit. Pl. Fl. Hal. 496 (1822). 
Betula torfacea, Custor, Flora, xx. pt. i. Beibl. 41 (1837). 
Betula alba, Hornemann, Fl. Dan. ix. t. 1467 (1823). — Smith 
& Sowerby, 1. c. xxxi. t. 2198. — Reichenbach, 'l. c. t. 623. — K. 
Koch, Dendr. ii. pt. i. 649. 
Betula alba, a vulgaris, Regel, Nouv. Mém. Soc. Nat. Mosc. xiii. 
75, t. 4, f. 1-18 (Monographia Betulacearum) (1860). 
Betula alba, subspec. verrucosa, « vulgaris, Regel, De Candolle 
Prodr. xvi. pt. ii. 163 (1868). 
and the Moor Birch, 
Betula alba, subspec. pubescens, Dippel, J. c. 174 (1892). 
Betula pubescens, Ehrhart, Beitr. vi. 98 (1791).— K. Koch, l. c. 
The White Birch and some closely related species which are not 
distinguished commercially are the most useful inhabitants of the 
The 
wood of Betula alba is white slightly tinged with red, straight- 
grained, and moderately hard, although it soon decays when placed 
in the ground or exposed to the action of the weather. It makes 
forests of the extreme northern parts of Europe and Asia. 
SILVA OF NORTH AMERICA. 
47 
Six or seven species inhabit Europe, the most 
Two species are 
excellent fuel, and for this purpose is used in great quantities in 
northern Europe in smelting furnaces ; it is also largely employed 
in making charcoal, in turnery, and in cabinet-making ; and in 
Russia the manufacture of wooden spoons from the wood of the 
Birch is a considerable industry in the Nizhni-Novgorod district 
(Industries of Russia, iii. 338). 
The bark, especially the corky outer layer found on the lower 
portion of the trunk, is rich in tannin and is employed in tanning 
leather ; a resinous balsamic essential oil distilled from it commu- 
nicates the peculiar color and the characteristic odor of Russia 
leather (Pallas, Reise, French ed. ii. 264). 
The production of Birch-bark oil is an important industry in 
some parts of northern Europe and in Siberia. It is obtained by a 
simple process of distillation, and the yield of the pure oil by 
weight is about one third of that of the bark used, about one hun- 
dred and fifty pounds of oil being obtained from twelve trees from 
thirty to fifty years old and of average size. Formerly the trees 
were cut down before the removal of the bark, but their increased 
value has caused the adoption of a system of cropping, the outer 
layers of bark being now stripped from the standing tree which 
survives the operation and yields successive crops of bark (Mathieu, 
Fl. Forestiere, ed. 3, 359.—Spons, Encyclopedia of the Industries, 
Arts, Manufactures, and Raw Commercial Products, ii. 1417). 
The peculiar resin, betulin, which is found in the white bark of 
the upper part of this tree and can be extracted by alcohol and 
crystallized, renders it impervious to water and preserves it uncor- 
rupted for ages against the action of alternating heat and cold, 
This quality makes the bark of the White 
Birch valuable for many purposes : it is used to envelop and pro- 
moisture and dryness. 
tect posts sunk in the ground and the sills of buildings, to cover 
the roofs of houses, the tops of walls, and the masonry of under- 
ground vaults, and in the manufacture of durable boxes, baskets, 
shoe-soles, and cords. It supplies the Laplander with a cloak 
which protects him from rain and snow, and the Russian peasant 
with boots and shoes (Loudon, Arh. Brit. iii. 1695). The starch 
contained in the cellular portion of the bark gives it alimentary 
importance in the extreme north, and mixed with the fat of the 
sea-wolf it is the principal food of the inhabitants of the coast of 
Kamtschatka during periods of famine (Lesseps, Travels in Kamt- 
schatka, English ed. ii. 89). 
From the sweet sap obtained in early spring from holes bored 
into the trunk of the tree vinegar is made, and a pleasant and 
wholesome effervescent wine is distilled. From the young branches, 
once the terror of youth, are made hoops, brooms, hurdles, baskets, 
The leaves, which are bitter to the taste, 
afford a yellow dye and have been used in medicine ; they are 
and the ties for fagots. 
sometimes dried while young and fed to cattle and sheep, although 
few animals browse upon them after they have attained their full 
size. 
The pure white bark of Betula alba, its graceful habit, its long 
slender pendulous branches, and its cheerful foliage, make it a 
popular inhabitant of parks and gardens of all cold countries, 
where, with its numerous varieties, it is very generally planted. 
Betula alba and some allied Old World species have been intro- 
duced into the northern United States, and here, although it is not 
long-lived, it is very hardy and grows rapidly, and is more often 
planted than any American species, especially in forms with pen- 
dulous branches or with laciniately cut leaves. 
