A tree, with aromatic bark and leaves, 70°—80° high, with a trunk 2°—5° in diameter, slender branches spreading almost at right angles, becoming pendulous toward the ends and gradually forming a narrow round-topped open graceful head, and branchlets light green, slightly viscid and pilose when they first appear, soon turning dark orange-brown, lustrous during the summer, bright red-brown in their first winter, becoming darker and finally dark dull brown slightly tinged with red.Winter-budsovoid, acute, about ¼′ long, with ovate acute light chestnut-brown loosely imbricated scales, those of the inner ranks becoming ½′—¾′ long.Barkon young stems and branches close, smooth, lustrous, dark brown tinged with red, and marked by elongated horizontal pale lenticels, becoming on old trunks ½′—¾′ thick, dull, deeply furrowed and broken into large thick irregular plates covered with closely appressed scales.Woodheavy, very strong and hard, close-grained, dark brown tinged with red, with thin light brown or yellow sapwood of 70—80 layers of annual growth; largely used for floors, in the manufacture of furniture and for fuel, and occasionally in ship and boat-building. Sweet birch-oil distilled from the wood and bark is used for medicinal purposes and for flavoring as a substitute for oil of wintergreen, and beer is obtained by fermenting the sugary sap.
Distribution.Rich uplands from southern Maine to northwestern Vermont, and eastern Ohio and southward to northern Delaware and along the Appalachian Mountains up to altitudes of 4000° to northern Georgia; in Alabama, and in eastern Kentucky and Tennessee; a common forest tree at the north, and of its largest size on the western slopes of the southern Alleghany Mountains.
×Betula JackiiSchn., a natural hybrid ofB. lentawithB. pumilaMichx., has appeared in the Arnold Arboretum.
Fig. 195
Leavesovate to oblong-ovate, acuminate or acute at apex, gradually narrowed to the rounded cuneate or rarely heart-shaped usually oblique base, sharply doubly serrate, when they unfold bronze-green or red, and pilose with long pale hairs above and on the under side of the midrib and veins, at maturity dull dark green above, yellow-green below, 3′—4½′ long, 1½′—2′ wide, with a stout midrib and primary veins covered below near the base of the leaf with short pale or rufous hairs; turning clear bright yellow in the autumn; petioles slender, pale yellow, hairy, ¾′—1′ long; stipules ovate, acute, light green tinged with pink above the middle, about ½′ long.Flowers: staminate aments during the winter ¾′—1′ long, about ⅛′ thick, with ovate rounded scales light chestnut-brown and lustrous above the middle, ciliate on the margins, becoming 3′—3½′ long and ⅓′ thick; pistillate amentsabout ⅔′ long, with acute scales, pale green below, light red and tipped with clusters of long white hair at apex, and pilose on the back.Fruit: strobiles erect, sessile, short-stalked, pubescent, 1′—1½′ long, about ¾′ thick; nut ellipsoidal to obovoid, about ⅛′ long, rather broader than its wing.
A tree, with slightly aromatic bark and leaves, occasionally 100° high, with a trunk 3°—4° in diameter, spreading and more or less pendulous branches forming a broad round-topped head, and branchlets at first green and covered with long pale hairs, light orange-brown and pilose during their first summer, becoming glabrous and light brown slightly tinged with orange, and ultimately dull and darker.Winter-budsabout ¼′ long, somewhat viscid and covered with loose pale hairs during the summer, becoming light chestnut-brown, acute, and slightly puberulous in winter.Barkof young stems and of the branches bright silvery gray or light orange color, very lustrous, separating into thin loose persistent scales more or less rolled on the margins, becoming on old trees ½′ thick, reddish brown, and divided by narrow irregular fissures into large thin plates covered with minute closely appressed scales, or sometimes dull yellowish brown (B. alleghaniensisBritt.).Woodheavy, very strong, hard, close-grained, light brown tinged with red, with thin nearly white sapwood; largely used for floors, in the manufacture of furniture, button and tassel moulds, boxes, the hubs of wheels, and for fuel.
Distribution.Moist uplands, and southward often in swamps; one of the largest deciduous-leaved trees of northeastern America; Newfoundland and along the northern shores of the Gulf of St. Lawrence to the valley of Rainy River, and southward to Long Island (Cold Spring Harbor) and western New York, Pennsylvania, northern Delaware, southeastern Ohio, northern Indiana, southwestern Wisconsin, northern, northeastern and central Iowa, and from the mountains of Virginia and West Virginia to the highest peaks of North Carolina and Tennessee at altitudes between 3000° and 5000°; very abundant and of its largest size in the eastern provinces of Canada and in northern New York and New England; small and rare in southern New England and southward.
×Betula PurpusiiSchn. believed to be a natural hybrid ofB. luteawithB. pumilavar.glanduliferaRegel has been found in Michigan and in Tamarack Swamps in Hennepin, Pine and Anoka Counties, Minnesota.
Fig. 196
Leavesrhombic-ovate, acute, abruptly or gradually narrowed and cuneate at base, doubly serrate, and on vigorous young branches often more or less laciniately cut into acutedoubly serrate lobes, when they unfold light yellow-green and pilose above and coated below, especially on the midrib and petioles, with thick white tomentum, at maturity thin and tough, 1½′—3′ long, 1′—2′ wide, deep green and lustrous above, glabrescent, pubescent or ultimately glabrous below, except on the stout midrib and remote primary veins; turning dull yellow in the autumn; petioles slender, slightly flattened, tomentose, about ½′ long; stipules ovate, rounded or acute at apex, pale green, covered below with white hairs.Flowers: staminate aments clustered, during the winter about ⅞ long and1/16′ thick, with ovate rounded dull chestnut-brown lustrous scales, becoming 2′—3′ long and ⅛′ thick; pistillate aments about ⅓′ long, with bright green ovate scales pubescent on the back, rounded or acute at apex, and ciliate with long white hairs.Fruitripening in May and June; strobiles cylindric, pubescent, 1′—1½′ long, ½′ thick, erect on stout tomentose peduncles ½′ long;nutovoid to ellipsoidal, ⅛′ in length, pubescent or puberulous at apex, about as broad as its thin puberulous wing, ciliate on the margin.
A tree, 80°—90° high, with a trunk often divided 15°—20° above the ground into 2 or 3 slightly diverging limbs, and sometimes 5° in diameter, slender branches forming in old age a narrow irregular picturesque crown, and branchlets coated at first with thick pale or slightly rufous tomentum gradually disappearing before winter, becoming dark red and lustrous, dull red-brown in their second year, and then gradually growing slightly darker until the bark separates into the thin flakes of the older branches; or often sending up from the ground a clump of several small spreading stems forming a low bushy tree.Winter-budsovoid, acute, about ¼′ long, covered in summer with thick pale tomentum, glabrous or slightly puberulous, lustrous and bright chestnut-brown in winter, the inner scales strap-shaped, light brown tinged with red, and coated with pale hairs.Barkon young stems and large branches thin, lustrous, light reddish brown or silvery gray, marked by narrow slightly darker longitudinal lenticels, separating freely into large thin papery scales persistent for several years, and turning back and showing the light pink-brown tints of the freshly exposed inner layers, becoming at the base of old trunks from ¾′—1′ thick, dark red-brown, deeply furrowed and broken on the surface into thick closely appressed scales.Woodlight, rather hard, strong, close-grained, light brown, with pale sapwood of 40—50 layers of annual growth; used in the manufacture of furniture, wooden ware, wooden shoes, and in turnery.
Distribution.Banks of streams, ponds, and swamps, in deep rich soil often inundated for several weeks at a time; near Manchester, Hillsboro County, New Hampshire, northeastern Massachusetts, Long Island, New York, southward to northern Florida through the region east of the Alleghany Mountains except in the immediate neighborhood of thecoast, through the Gulf states to the valley of the Navasota River, Brazos County, Texas, and through Arkansas, eastern Oklahoma, southeastern Kansas, and Missouri to Tennessee and Kentucky, southern and eastern Iowa, southern Minnesota, the valley of the Eau Claire River, Eau Claire County, Wisconsin, southern Illinois, the valley of the Kankakee River, Indiana, and southern Ohio; the only semiaquatic species and the only species ripening its seeds in the spring or early summer; attaining its largest size in the damp semitropical lowlands of Florida, Louisiana, and Texas; the only Birch-tree of such warm regions.
Often cultivated in the northeastern states as an ornamental tree, growing rapidly in cultivation.
Fig. 197
Leavesnearly triangular to rhombic, long-pointed, coarsely doubly serrate with stout spreading glandular teeth except at the broad truncate or slightly cordate or cuneate base, thin and firm, dark green and lustrous and somewhat roughened on the upper surface early in the season by small pale glands in the axils of the conspicuous reticulate veinlets, 2½′—3′ long, 1½′—2½′ wide, with a stout yellow midrib covered with minute glands, and raised and rounded on the upper side, and obscure yellow primary veins; turning pale yellow in the autumn; petioles slender, terete, covered with black glands, often stained with red on the upper side, ¾′—1′ long; stipules broadly ovate, acute, membranaceous, light green slightly tinged with red.Flowers: staminate aments usually solitary or rarely in pairs, 1¼′—1½′ long, about ⅛′ thick during the winter, becoming 2½′—4′ long, with ovate acute apiculate scales; pistillate aments slender, as long as their glandular peduncles about ½′ in length, with ovate acute pale green glandular scales.Fruit: strobiles cylindric, pubescent, obtuse at apex, about ¾′ long and ⅓′ thick, pendant or spreading on slender stems; nut ellipsoidal to obovoid, acute or rounded at base, a little narrower than its obovate wing.
A short-lived tree, 20°—30° or exceptionally 40° high, with a trunk rarely 18′ in diameter, short slender often pendulous more or less contorted branches usually clothing the stem to the ground and forming a narrow pyramidal head, and branchlets roughened by small raised lenticels, resinous-glandular when they first appear, gradually growing darker, bright yellow and lustrous before autumn like the young stems, bright reddish brown during their first winter, and ultimately white near the trunk; often growing in clusters of spreading stems springing from the stumps of old trees.Winter-budsovoid, acute, pale chestnut-brown, glabrous, about ¼′ long.Barkabout ⅓′ thick, dull chalky white on the outer surface, bright orange on the inner, close and firm, with dark triangular markings at theinsertion of the branches, becoming at the base of old trees thicker, nearly black, and irregularly broken by shallow fissures.Woodlight, soft, not strong, close-grained, not durable, light brown, with thick nearly white sapwood; used in the manufacture of spools, shoe-pegs and wood pulp, for the hoops of barrels, and largely for fuel.
Distribution.Dry gravelly barren soil or on the margins of swamps and ponds; Prince Edward Island, Nova Scotia, New Brunswick, and the valley of the lower St. Lawrence River southward to northeastern, central and on South Mountain, Franklin County, Pennsylvania, and northern Delaware, and westward through northern New England and New York, ascending sometimes to altitudes of 1800°, to the southern shores of Lake Ontario, and at the foot of Lake Michigan, Indiana; rare and local in the interior, very abundant in the coast region of New England and the middle states; springing up in great numbers on abandoned farm-lands or on lands stripped by fire of their original forest covering; most valuable in its ability to grow rapidly in sterile soil and to afford protection to the seedlings of more valuable and less rapid-growing trees.
A form with deeply divided leaves (var.laciniataLoud.) and one with purple leaves (var.purpureaE & B) are occasionally cultivated.
A shrub believed to be a natural hybrid ofB. populifoliawithB. pumilaMichx. has been found near Mt. Mansfield, Vermont.
Fig. 198
Leavesovate, long-pointed, broadly or narrowly concave-cuneate at the entire often unequal base, sharply mostly doubly serrate above with straight or incurved glandular often apiculate teeth, covered above when they unfold with pale deciduous glands, at maturity dull bluish green above, pale yellow-green below, and sparingly villose along the under side of the slender yellow midrib and primary veins, 2′—2½′ long, 1′—1½′ wide; petioles slender, ¾′—1¼′ long, yellow more or less deeply tinged with red.Flowers: staminate aments usually in pairs, or singly or in 3’s, 1¼′—2′ long, about3/16′ thick, with ovate rounded short-pointed scales; pistillate aments slender, about ⅓′ long, with acuminate pale green much reflexed scales.Fruit: strobiles cylindric, pubescent, slightly narrowed at the obtuse apex, about 1′ long and ¼′ thick, pendant on slender peduncles ¼′—½′ in length;nutellipsoidal, much narrower than its broad wing.
A tree, rarely more than 30° high, with a trunk 8′—10′ in diameter, small ascending finally spreading branches, and slender branchlets marked by numerous small raised pale lenticels, purplish and sparingly villose when they first appear, soon glabrous, becomingbright red-brown; often forming clumps of several stems.Barkthin, white tinged with rose, lustrous, not readily separable into layers, the inner bark light orange color.
Distribution.Moist slopes, Stratton and Windham, Windham County, Vermont, at altitudes of about 1800° (W. H. Blanchard), Haystack Mountain, Aroostook County, Maine (M. L. Fernald); the American representative of the EuropeanBetula pendulaRoth., and probably widely distributed over the hills of northern New England and eastern Canada. Perhaps with its variety best considered a natural hybrid betweenB. papyriferaandB. populifolia.
Apparently passing into a form with larger leaves often rounded and truncate at the broad base, 3′—3½′ long and 2′ wide, stouter staminate aments, and strobiles frequently 1½′ long and ½′ thick (var.BlanchardiiSarg. fig. 198 A). This under favorable conditions is a tree 60°—70° high, with a trunk 18′ in diameter; common withBetula cœruleaat Windham and Stratton, Vermont (W. H. Blanchard), and on a hill near the coast in Washington County, Maine (M. L. Fernald).
Fig. 199
Leavesovate, acute or acuminate with a short broad point, coarsely usually doubly and often very irregularly serrate except at the rounded abruptly cuneate or gradually narrowed base, bright green, glandular-resinous, pubescent and clothed below on the midrib and primary veins and on the petioles with long white hairs when they unfold, at maturity thick and firm, dull dark green and glandless or rarely glandular on the upper surface, light yellow-green and glabrous or puberulous, with small tufts of pale hairs in the axils of the primary veins and covered with many black glands on the lower surface, 2′—3′ long, 1½′—2′ wide, with a slender yellow midrib marked, like the remote primary veins, with minute black glands, turning light clear yellow in the autumn; petioles stout, yellow, glandular, glabrous or pubescent, ½′—¾′ long; stipules ovate, acute, ciliate on the margins with pale hairs, light green.Flowers: staminate aments clustered during the winter, ¾′—1¼′ long, about ⅛′ thick, with ovate, acute scales light brown below the middle, dark red-brown above it, becoming 3½′—4′ long, and about ⅓′ thick; pistillate aments 1′—1¼′ long, about1/16′ thick, with light green lanceolate scales long-pointed and acute or rounded at apex; styles bright red.Fruit: strobiles cylindric, glabrous, about 1½′ long and ⅓′ thick, hanging on slender stalks, their scales very rarely entire (var.elobataSarg.); nut ellipsoidal, about1/16′ long, much narrower than its thin wing.
A tree, usually 60°—70° tall, with a trunk 2°—3° in diameter, becoming in old age, or when crowded by other trees, branchless below and supporting a narrow open head ofshort pendulous branches, and branchlets at first light green, slightly viscid, marked by scattered orange-colored oblong lenticels and covered with long pale hairs, dark orange color and glabrous or pubescent during the summer, becoming dull red in their first winter, gradually growing dark orange-brown, lustrous for four or five years and ultimately covered with the white papery bark of older branches.Winter-budsobovoid, acute, about ¼′ long, pubescent below the middle and coated with resinous gum at midsummer, dark chestnut-brown, glabrous and slightly resinous during the winter, their inner scales becoming strap-shaped, rounded at apex, about ½′ long and ⅛′ wide.Barkon young trunks and large limbs thin, creamy white or rarely bronze color or orange-brown and lustrous on the outer surface, bright orange color on the inner, marked by long narrow slightly darker colored raised lenticels, separating into thin papery layers, pale orange color when first exposed to the light, becoming on old trunks for a few feet above the ground sometimes ½′ thick, dull brown or nearly black, sharply and irregularly furrowed and broken on the surface into thick closely appressed scales.Woodlight, strong, hard, tough, very close-grained, light brown tinged with red, with thick nearly white sapwood; largely used for spools, shoe-lasts, pegs, and in turnery, the manufacture of wood-pulp, and for fuel. The tough resinous durable bark impervious to water is used by all the northern Indians to cover their canoes and for baskets, bags, drinking-cups, and other small articles, and often to cover their wigwams in winter.
Distribution.Rich wooded slopes and the borders of streams, lakes, and swamps scattered through forests of other trees; Labrador to the southern shores of Hudson’s Bay, and southward to Long Island, New York, northern Pennsylvania, central Michigan, northern Wisconsin, northern-central Iowa, eastern Nebraska, North and South Dakota and Wyoming; common in the maritime provinces of Canada and North of the Great Lakes, and in northern New England and New York; small and comparatively rare in the coast region of southern New England and southward; on the highest mountains of New England and northward the var.minorS. Wats and Cov. is common as a small shrub.
Often planted in the northeastern states as an ornamental tree.
×Betula SandbergiiBritt. and its f.maximaRosend. generally believed to be natural hybrids ofB. papyriferaandB. pumilavar.glanduliferaRegl. occur in Tamarack swamps in Hennepin County, Minnesota.
Passing into the following varieties.
Fig. 200
Leavesovate, abruptly pointed and acuminate or acute at apex, cordate at base, coarsely doubly serrate, glabrous or pilose on the under side of the midrib and veins, often furnishedbelow with axillary tufts of pale hairs, 1½′—3′ long, 1′—2½′ wide; petioles glabrous or rarely villose, ½′—¾′ in length.Fruit: strobiles ¾′—2′ long and ¼′—½′ thick, on villose peduncles up to ¾′ in length; scales glabrous or pubescent.
A tree rarely more than 30° tall, with slender glabrous or pubescent branchlets, and at high altitudes on the New England mountains reduced to a low shrub.Barkseparating in thin layers, white or dark reddish brown.
Distribution.Labrador and Newfoundland to northern New England, and westward to the shores of Green Bay, Wisconsin, and those of Lake Superior, Minnesota (Grand Marais, Cook County); on Mt. Mitchell, North Carolina, at an altitude of 5550° (W. W. Ashe).
Betula subcordataRydb.
Fig. 201
Leavesovate, acute or acuminate at apex, slightly cordate or rounded at base, rarely slightly lobed above the middle, finely often doubly serrate with teeth pointing forward or spreading, glabrous, 2′—2½′ long, 1′—1½′ wide; petioles sparingly villose or glabrous, ½′—¾′ in length.Fruit: strobiles drooping on slender peduncles 1′—1½′ long, about ⅓′ thick, their scales puberulous, ciliate on the margins, the middle lobe acute, rather longer than the broad truncate lateral lobes; nut obovoid, cuneate at base,1/12′ long, narrower than its wings.
A tree 25°—40° or occasionally 60° high, with a trunk 12′—18′ in diameter, and slightly glandular glabrous red-brown branchlets.Barkseparating freely into thin layers, white or occasionally dark reddish brown or orange color.
Distribution.Alberta (Crow Nest Pass, neighborhood of Jasper and Cypress Hills), through northern Montana and Idaho to western Washington, northeastern Oregon (Minum River Valley) and British Columbia.
Betula montanensisButler.
Fig. 202
Leavesbroadly ovate, acute at apex, truncate or rounded at base to oblong-ovate or lanceolate and long-pointed and acuminate at apex, narrowed and rounded at base, coarsely doubly serrate, thick, dark green above, paler, sparingly pubescent and furnished withconspicuous tufts of axillary hairs below, 3′—5′ long, 2′—2¼′ wide; petioles puberulous, ¾′—1′ in length.Flowersunknown.Fruit: strobiles cylindric, 1¾′—2′ long, ½′ thick, pendent on puberulous peduncles ½′—¾′ in length, their scales puberulous, finely ciliate on the margins, the slender base of those below the middle of the ament rather more than twice as long as the expanded upper portion of the scale.
A tree 40°—50° high, with a trunk 12′—18′ in diameter, and slender branchlets red-brown, lustrous, marked by small pale lenticels and puberulous during their first season.Winter-budsnarrow-obovoid, acuminate, dark red-brown, resinous, ⅓′ long.Barkwhite, or dark gray or brown.
Distribution.Shore of Yellow Bay, Flathead Lake, Flathead County, Montana, and at Sandpoint, Bonner County, Idaho.
Betula occidentalisHook.
Fig. 203
Leavesovate, acute, or abruptly acuminate at apex, rounded or occasionally cordate or rarely cuneate at the broad base, coarsely and generally doubly serrate with straight or incurved glandular teeth, thin and firm in texture, dull dark green above, pale yellow-green below, and puberulous on both sides of the stout yellow midrib and slender primary veins, 3′—4′ long, 1½′—2′ wide; petioles stout, glandular, at first tomentose, ultimately pubescent or puberulous, about ¾′ long; stipules oblong-obovate, rounded and acute or apisculate at apex, ciliate on the margin, puberulous, glandular-viscid.Flowers: staminate aments during the winter about ¾′ long and ⅛′ thick, with ovate scales rounded or abruptly narrowed and acute at apex; puberulous on the outer surface, ciliate on the margins, becoming 3′—4′ long and about ¼′ thick; pistillate aments about 1′ long and1/16′ thick, with acuminate bright green scales.Fruit: strobiles cylindric, puberulous, spreading, 1¼′—1½′ long, ¼′—½′ thick, on stout peduncles ¾′ in length, their scales ciliate on the margins; nut oval, about1/16′ in length, and nearly as wide as its wings.
A tree, 100°—120° high, with a trunk 3°—4° in diameter, comparatively small branches often pendulous on old trees, and pale orange-brown branchlets more or less glandular and coated with long pale hairs when they first appear, becoming bright orange-brown and nearly destitute of glands during their first winter, and in their second year orange-brown, glabrous, and very lustrous.Winter-budsacute, bright orange-brown, ⅛′—¼′ long, their light brown inner scales sometimes becoming ¾′ in length.Barkthin, marked by long oblong horizontal raised lenticels, dark orange-brown or white, very lustrous, separatingfreely into thin papery layers displaying in falling the bright orange-yellow inner bark.
Distribution.Banks of streams and lakes; southwestern British Columbia and northwestern Washington and eastward through eastern Washington and northern Idaho to northern Montana west of the continental divide; nowhere common and probably of its largest size on the alluvial banks of the lower Fraser River, and on the islands of Puget Sound.
Betula kenaicaEvans.
Fig. 204
Leavesovate, acute or acuminate, broadly cuneate or somewhat rounded at the entire base, irregularly coarsely often doubly serrate, glabrous, dark dull green above, pale yellow-green below, 1½′—2′ long, 1′—1¾′ wide, with a slender yellow midrib and 5 pairs of thin primary veins; petioles slender, ¾′—1′ long.Flowers: staminate aments clustered, 1′ long,with ovate acute scales apiculate at apex, puberulous on the outer surface; pistillate aments, ⅓′—½′ long, about1/16′ thick, on slender glandular pubescent peduncles ½′—¾′ in length; scales acuminate light green strongly reflexed; styles bright red.Fruit: strobiles cylindric, glabrous, 1′ long, their scales ciliate on the margins; nut oval, somewhat narrower than its thin wing.
A tree, 30°—40° high, with a trunk 12′—20′ in diameter, wide-spreading branches, stout branchlets marked by numerous small pale lenticels, bright red-brown during 2 or 3 years, gradually becoming darker.Barkthin, more or less furrowed, very dark brown or nearly black near the base of the trunk, grayish white or light reddish brown and separating into thin layers higher on the stem and on the branches.
Distribution.Coast of Alaska from Cook Inlet southward to the head of the Lynn Canal.
Fig. 205
Leavesrhombic to deltoid-ovate, long-pointed, truncate, rounded or broadly cuneate, or on leading shoots occasionally cordate at the entire base, coarsely and often doubly glandular-serrate, thin, dark green above, pale and yellow-green below, 1½′—3′ long, 1′—1½′ wide, with a slender midrib and primary veins pubescent or ultimately glabrous below; petioles often bright red, somewhat hairy at first, finally glabrous, about 1′ long;Flowers: staminate aments clustered, sessile, 1′ long, ⅛′ thick, with ovate acuminate scales puberulous on the outer surface, and bright red, with yellow margins; pistillate aments slender, cylindric, glandular, 1′ long, ⅛′ thick, on stout peduncles nearly ½′ in length.Fruit: strobiles glabrous, pendulous or spreading, 1′—1¼′ long, ⅓′—½′ thick, their scales ciliate on the margins; nut oval, narrower than its broad wing.
A tree, usually 30°—40°, occasionally 80°, high, with a trunk 6′—12′ in diameter, slender erect and spreading or pendulous branches, and glabrous bright red-brown branchlets more or less thickly covered during their first year with resinous glands sometimes persistent until the second or third season.Winter-budsovoid, obtuse at the gradually narrowed apex, about ¼′ long, with light red-brown shining outer scales sometimes ciliate on the margins, and oblong rounded scarious inner scales hardly more than ½′ long when fully grown.Barkthin, marked by numerous elongated dark slightly raised lenticels, dull reddish brown or sometimes nearly white on the outer surface, light red on the inner surface, close and firm, finally separable into thin plate-like scales.
Distribution.Valley of the Saskatchewan northwestward to the valley of the Yukon,growing sparingly near the banks of streams in forests of coniferous trees and in large numbers on sunny slopes and hillsides; the common Birch-tree of the Yukon basin.
×Betula commixtaSarg., a shrub, growing on the tundra near Dawson, Yukon Territory, is believed to be a hybrid betweenB. alaskanaandB. glandulosaMichx.
Fig. 206
Leavesovate, acute or acuminate, sharply and often doubly serrate, except at the rounded or abruptly cuneate often unequal base, and sometimes slightly laciniately lobed, pale green, pilose above, and covered by conspicuous resinous glands when they unfold, at maturity thin and firm, dark dull green above, pale yellow-green, rather lustrous and covered by minute glandular dots below, 1′—2′ long, ¾′—1′ wide, with a slender pale midrib, remote glandular veins, and rather conspicuous reticulate veinlets; turning dull yellow in the autumn; petioles stout, puberulous, light yellow, glandular-dotted, flattened on the upper side, often flushed with red, ⅓′—½′ long; stipules broadly ovate, acute or rounded at apex, slightly ciliate, bright green, soon becoming pale and scarious.Flowers: staminate aments clustered, ½′—¾′ long and1/16′ thick during the winter, with ovate acute light chestnut-brown scales pale and slightly ciliate on the margins, becoming 2′—2½′ long, and about ⅛′ thick, with apiculate scales; pistillate aments short-stalked, about ¾′ long, with ovate acute green scales; styles bright red.Fruit: strobiles cylindric, rather obtuse, puberulous or nearly glabrous, 1′—1¼′ long, ½′ thick, erect or pendulous on slender glandular peduncles, ¼′ to nearly ¾′ in length; their scales ciliate, puberulous, the lateral lobes ascending, shorter than the middle lobe; nut ovoid or obovoid, puberulous at apex, nearly as wide as its wing.
A tree 20°—25° high with a short trunk, rarely more than 12′ or 14′ in diameter, ascending spreading and somewhat pendulous branches forming a broad open head, and slender branchlets, when they first appear light green glabrous or puberulous and covered with lustrous resinous glands persistent during their second season, and dark red-brown in their first winter; more commonly shrubby, with many thin spreading stems forming open clusters, 15°—20° high; often much lower, and frequently crowded in almost impenetrable thickets.Winter-budsovoid, acute, very resinous, chestnut-brown, ¼′ long.Barkabout ¼′ thick, dark bronze color, very lustrous, marked by pale brown longitudinal lenticels becoming on old trunks often 6′—8′ long and ¼′ wide.Woodsoft and strong, light brown, with thick lighter-colored sapwood; sometimes used for fuel and fencing.
Distribution.Moist soil near the banks of streams usually in mountain cañons; generallydistributed, although nowhere very common: valley of the Saskatchewan (Saskatoon), Saskatchewan, westward to the basin of the upper Fraser and Pease Rivers, British Columbia, southward along the Rocky Mountains to eastern Utah, northern New Mexico and Arizona, the valleys of the Shasta region and the eastern slope of the Sierra Nevada, northern California, and eastward in the United States to the eastern foothills of the Rocky Mountains of Colorado, the Black Hills of South Dakota, and northwestern Nebraska. Passing into
Betula PiperiBritt.
Fig. 207
A tree occasionally 50°—60° high with a tall trunk 12′—18′ in diameter, short spreading branches, and usually longer and often narrower strobiles.
Distribution.Spokane, Spokane County, Almota and Pullman, Whitman County, eastern Washington.
Fig. 208
Leavesbroad-ovate to elliptic, acute, rounded or abruptly short-pointed at apex, coarsely serrate except at the cuneate base, thick, glabrous, dark green above, pale below, reticulate-venulose,the veinlets more conspicuous on the lower surface, 1′—1½′ long, ¾′—1½′ wide; petioles slender, glabrous ⅕′—⅓′ in length; stipules scarious, ovate-oblong, rounded at apex.Flowers:staminate aments usually solitary or in pairs, sessile, 1′—1¼′ long, ⅕′ thick, with broadly ovate pubescent dark red scales acute and apiculate at apex; pistillate aments ½′ long, about1/12′ thick, with acute light green scales.Fruit:strobiles pendulous on peduncles ⅓′—½′ long, cylindric, ¾′ in length, about ⅙′ thick, their scales glabrous longer than broad, the lobes narrowed at the rounded apex, ciliate, the lateral slightly spreading, one third shorter than the terminal lobe.
A tree 18°—20° high, with a trunk rarely more than 6′ in diameter, and slender red glabrous branchlets thickly covered with circular white glands.Barkclose, chestnut-brown, marked by conspicuous horizontal white lenticels, about ⅕′ thick.
Distribution.Swamps near Dawson, Yukon Territory, forming jungles withBetula glandulosaMichx.,B. alaskanaSarg., and various Willows; as a large shrub in Jasper Park near Jasper, Alberta.
Trees and shrubs, with astringent scaly bark, soft straight-grained wood, naked stipitate winter-buds formed in summer and nearly inclosed by the united stipules of the first leaf, becoming thick, resinous, and dark red. Leaves open and convex in the bud, falling without change of color; stipules of all but the first leaf ovate, acute, and scarious. Flowers vernal, or rarely opening in the autumn from aments of the year, in 1—3-flowered cymes in the axils of the peltate short-stalked scales of stalked aments formed in summer or autumn in the axils of the last leaves of the year or of those of minute leafy bracts; staminate aments elongated, pendulous, paniculate, naked and erect during the winter, each staminate flower subtended by 3—5 minute bractlets adnate to the scales of the ament, and composed of a 4-parted calyx, and 1—3 or usually 4 stamens inserted on the base of the calyx opposite its lobes, with short simple filaments; pistillate aments ovoid or oblong, erect, stalked, produced in summer in the axils of the leaves of a branch developed from the axils of an upper leaf of the year, and below the staminate inflorescence, inclosed at first in the stipules of the first leaf, emerging in the autumn and naked during the winter, or remaining covered until early spring; pistillate flowers in pairs, each flower subtended by 2—4 minute bractlets adnate to the fleshy scale of the ament becoming at maturity thick and woody, obovate, 3—5-lobed or truncate at the thickened apex, forming an ovoid or subglobose strobile persistent after the opening of its closely imbricated scales; calyx 0; ovary compressed; nut minute, bright chestnut-brown, ovoid to oblong, flat, bearing at the apex the remnants of the style, marked at the base by a pale scar, the outer coat of the shell produced into lateral wings often reduced to a narrow membranaceous border.
Alnus inhabits swamps, river bottom-lands, and high mountains, and is widely and generally distributed through the northern hemisphere, often forming the most conspicuous feature of vegetation on mountain slopes, ranging at high altitudes southward in the New World through Central America to Colombia, Peru, and Bolivia, and to upper Assam and Japan in the Old World. Of the eighteen or twenty species now recognized nine are North American; of these, six attain the size and habit of trees. Of the exotic species,Alnus vulgarisHill., a common European, north African, and Asiatic timber-tree, was introduced many years ago into the northeastern states, where it has become locally naturalized. The wood of Alnus is very durable in water, and the astringent bark and strobiles are used in tanning leather and in medicine.
Alnusis the classical name of the Alder.
Alnus sitchensisSarg.
Fig. 209
Leavesovate, acute, full and rounded and often unsymmetrical and somewhat oblique or abruptly narrowed and cuneate at base, divided into numerous short acute lateral lobes, sharply and doubly serrate with straight glandular teeth, glandular-viscid as they unfold, at maturity membranaceous, yellow-green on the upper surface, pale and very lustrous on the lower surface, glabrous, or villose along the under side of the stout midrib with short brown hairs also forming tufts in the axils of the numerous slender primary veins, 3′—6′ long, 1½′—4′ wide; petioles stout, grooved, abruptly enlarged at the base, ½′—¾′ in length; stipules oblong to spatulate, rounded and apiculate at apex, puberulous, about ¼′ long.Flowers: staminate aments sessile, in pairs in the axils of the upper leaves sometimes reduced to small bracts, and single in the axil of the leaf next below, during the winter about ½′ long and ⅛′ thick, with dark red-brown shining puberulous apiculate scales, becoming when the flowers open from spring to midsummer 4′ or 5′ long, with a puberulous light red rachis and ovate acute apiculate 3-flowered scales; calyx-lobes rounded, shorter than the 4 stamens; pistillate aments in elongated panicles, inclosed during winter in buds formed the previous summer in the axils of the leaves of short lateral branchlets, long-pedunculate, ⅓′ long, ⅙′ thick.Fruit: strobiles on slender peduncles in elongated sometimes leafy panicles 4′—6′ in length, oblong, ½′—⅝′ long, about ⅓′ thick, their truncate scales thickened at the apex; nut oval, about as wide as its wings.
A tree, sometimes 40° high, with a trunk 7′—8′ in diameter, short small nearly horizontal branches forming a narrow crown, and slender slightly zigzag branchlets puberulous and very glandular when they first appear, bright orange-brown and lustrous and marked by numerous large pale lenticels during their first season, much roughened during their second year by the elevated crowded leaf-scars, becoming light gray.Winter-budsacuminate, dark purple, covered especially toward the apex with close fine pubescence, about ½′ long.Barkthin bluish gray, with bright red inner bark; often a shrub only a few feet tall spreading into broad thickets.
Distribution.Northwest coast from the borders of the Arctic Circle to the high mountains of northern California; common in the valley of the Yukon and eastward through British Columbia to Alberta, and through Washington and Oregon to the western slopes of the Rocky Mountains in Montana; at the north with dwarf Willows, forming great thickets; in southeastern Alaska often a tall tree on rich moist bottom-lands near the mouths of mountain streams, and at the upper limits of tree growth a low shrub; very abundant in the valley of the Yukon on the wet banks of streams and often arborescent in habit; in British Columbia and the United States generally smaller and a shrub, growing usually only at altitudes of more than 3000° above the sea, and often forming thickets on the banks of streams and lakes.
Alnus oregonaNutt.