Part 31

Leaves ovate, 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, about 1/16′ 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. _elobata_ Sarg.); nut ellipsoidal, about 1/16′ 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 of short 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-buds obovoid, 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. Bark on 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. Wood light, 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. _minor_ S. Wats and Cov. is common as a small shrub.

Often planted in the northeastern states as an ornamental tree.

× _Betula Sandbergii_ Britt. and its f. _maxima_ Rosend. generally believed to be natural hybrids of _B. papyrifera_ and _B. pumila_ var. _glandulifera_ Regl. occur in Tamarack swamps in Hennepin County, Minnesota.

Passing into the following varieties.

Betula papyrifera var. cordifolia Fern.

Leaves ovate, 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 furnished below 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. Bark separating 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 papyrifera var. subcordata Sarg.

_Betula subcordata_ Rydb.

Leaves ovate, 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. Bark separating 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 papyrifera var. montanensis Sarg.

_Betula montanensis_ Butler.

Leaves broadly 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 with conspicuous tufts of axillary hairs below, 3′—5′ long, 2′—2¼′ wide; petioles puberulous, ¾′—1′ in length. Flowers unknown. 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-buds narrow-obovoid, acuminate, dark red-brown, resinous, ⅓′ long. Bark white, or dark gray or brown.

Distribution. Shore of Yellow Bay, Flathead Lake, Flathead County, Montana, and at Sandpoint, Bonner County, Idaho.

Betula papyrifera var. occidentalis Sarg.

_Betula occidentalis_ Hook.

Leaves ovate, 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 and 1/16′ 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, about 1/16′ 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-buds acute, bright orange-brown, ⅛′—¼′ long, their light brown inner scales sometimes becoming ¾′ in length. Bark thin, marked by long oblong horizontal raised lenticels, dark orange-brown or white, very lustrous, separating freely 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 papyrifera var. kenaica A. Henry. Red Birch. Black Birch.

_Betula kenaica_ Evans.

Leaves ovate, 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, about 1/16′ 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. Bark thin, 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.

7. Betula alaskana Sarg. White Birch.

Leaves rhombic 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-buds ovoid, 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. Bark thin, 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 commixta_ Sarg., a shrub, growing on the tundra near Dawson, Yukon Territory, is believed to be a hybrid between _B. alaskana_ and _B. glandulosa_ Michx.

8. Betula fontinalis Sarg. Black Birch.

Leaves ovate, 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 and 1/16′ 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-buds ovoid, acute, very resinous, chestnut-brown, ¼′ long. Bark about ¼′ thick, dark bronze color, very lustrous, marked by pale brown longitudinal lenticels becoming on old trunks often 6′—8′ long and ¼′ wide. Wood soft 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; generally distributed, 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 fontinalis var. Piperi Sarg.

_Betula Piperi_ Britt.

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.

9. Betula Eastwoodæ Sarg.

Leaves broad-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, about 1/12′ 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. Bark close, chestnut-brown, marked by conspicuous horizontal white lenticels, about ⅕′ thick.

Distribution. Swamps near Dawson, Yukon Territory, forming jungles with _Betula glandulosa_ Michx., _B. alaskana_ Sarg., and various Willows; as a large shrub in Jasper Park near Jasper, Alberta.

4. ALNUS L. Alder.

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 vulgaris_ Hill., 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.

_Alnus_ is the classical name of the Alder.

CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES.

Flowers opening in spring with or after the leaves; stamens 4; pistillate aments inclosed during the winter; wing of the nut broad; leaves ovate, sinuately lobed, lustrous on the lower surface. 1. A. sinuata (B, F, G). Flowers opening in winter or early spring before the unfolding of the leaves; pistillate aments usually naked during the winter. Wing of the nut broad; leaves ovate or elliptic, rusty-pubescent on the lower surface; pistillate aments often inclosed during the winter; stamens 4. 2. A. rubra (B, G). Wing of the nut reduced to a narrow border. Stamens 4; leaves oblong-ovate, glabrous or puberulous on the lower surface. 3. A. tenuifolia (B, F, G). Stamens usually 2, or 3. Leaves ovate or oval. 4. A. rhombifolia (B, F, G). Leaves oblong-lanceolate, acute. 5. A. oblongifolia (H). Flowers opening in autumn from aments of the year; stamens 4; wing of the nut reduced to a narrow border; leaves oblong-ovate or obovate, dark green and lustrous above, pale yellow-green below. 6. A. maritima (A).

1. Alnus sinuata Rydb. Alder.

_Alnus sitchensis_ Sarg.

Leaves ovate, 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.