Leaves cordate or truncate at base, 3-lobed by broad shallow sinuses, the lobes acute or obtuse, entire or slightly lobulate, sparingly hairy on the upper surface and thickly coated with dense pale tomentum on the lower surface when they unfold, and at maturity thick and firm, dark green and lustrous above, pale and pubescent below, especially on the stout nerves and veins, or rarely glabrous, 2′—5′ in diameter; turning in the autumn before falling yellow and scarlet; petioles stout, 1′—2′ in length, glabrous, often red after midsummer, encircling the branchlet with their large base villose on the inner surface. Flowers appearing with the leaves on long slender drooping villose pedicels, in short-stalked corymbs; calyx campanulate, yellow, sparingly hairy with long pale hairs, about ¼′ long, with broad rounded lobes, often persistent under the fruit; corolla 0; stamens 7 or 8, much longer than the calyx, in the pistillate flower shorter than the calyx; ovary usually glabrous, with long spreading stigmatic lobes, rudimentary in the staminate flower. Fruit often rose-colored at midsummer, green at maturity, glabrous or rarely sparingly hairy, with spreading or erect wings ½′—1′ long; seeds smooth, light red-brown, about ¼′ long.
A tree, occasionally 30°—40° high, with a trunk 8′—10′ in diameter, stout usually erect branches, and slender glabrous bright red branchlets marked by numerous small pale lenticels and nearly encircled by the narrow leaf-scars, with conspicuous bands of long pale hairs in their axils. Winter-buds acute or acuminate, about 1/16′ long, bright red-brown, with puberulous-ciliate outer scales and obovate apiculate inner scales sometimes ½′ long when fully grown. Bark of the trunk thin, dark brown, separating on the surface into plate-like scales. Wood heavy, hard, close-grained, bright brown or nearly white, with thick sapwood.
Distribution. Banks of mountain streams usually at altitudes of 5000°—6000° above the sea; on the Salt River Mountains, western Wyoming; valley of the Columbia River in northern Montana, southeastern Idaho (Pocatello, Oneida County), Wasatch Mountains, Utah, mountains of Arizona and of southern New Mexico; on the Guadalupe Mountains, western Texas, and on the Wichita Mountains, southwestern Oklahoma (G. W. Stevens); in Coahuila; rare and local.
Occasionally cultivated; hardy in the Arnold Arboretum.
9. Acer nigrum Michx. Black Maple.
Leaves generally 3 or occasionally 5-lobed, with abruptly short-pointed acute or acuminate lobes, undulate and narrowed from broad shallow sinuses and rarely furnished with short lateral spreading lobules, cordate at base with a broad sinus usually more or less closed by the approximation or imbrication of the basal lobes, occasionally 3-lobed with a broad long-acuminate nearly entire terminal lobe, and rounded or slightly cordate at base (var. Palmeri Sarg.), covered below when they unfold with hoary tomentum and above with caducous pale hairs, and at maturity thick and firm in texture, dull green on the upper surface, yellow-green and soft-pubescent, especially along the yellow veins on the lower surface, and 5′—6′ long and wide, with drooping sides; turning bright clear yellow in the autumn; petioles stout, tomentose or pubescent, sometimes becoming glabrous at maturity, usually pendent, 3′—5′ in length, much enlarged at base, frequently nearly inclosing the buds, in falling leaving narrow scars almost encircling the branchlet and furnished in their axils with tufts of long pale hairs; stipules triangular and dentate or foliaceous, sessile or stipitate, oblong, acute, tomentose or pubescent, sometimes slightly lobed, frequently 1½′ long. Flowers yellow, about ¼′ long, on slender hairy pedicels 2½′—3′ long, in many-flowered nearly sessile umbel-like corymbs, the staminate and pistillate in separate or in the same cluster on the same or on different trees; calyx broad-campanulate, 5-lobed by the partial union of the sepals, pilose on the outer surface near the base; corolla 0; stamens 7 or 8, with slender glabrous filaments, in the staminate flower nearly twice as long as the calyx and in the pistillate flower shorter than the calyx; ovary obtusely lobed, pale green, covered with long scattered hairs, minute in the sterile flower. Fruit glabrous, with convergent or wide-spreading wings ½′—1′ long; seeds smooth, bright red-brown, ¼′ long.
A tree, sometimes 80° high, with a trunk frequently 3° in diameter, stout spreading or often erect branches, and stout branchlets marked by oblong pale lenticels, orange-green and pilose with scattered pale caducous hairs when they appear, orange or orange-brown and lustrous during their first year, becoming dull pale gray-brown the following season. Winter-buds sessile, ovoid, acute, ⅛′ long, with dark red-brown acute scales hoary-pubescent on the outer surface and often slightly ciliate on the margins, and yellow puberulous inner scales, ½′—1′ long at maturity. Bark of young stems and of the branches thin, smooth, pale gray, becoming on old trunks thick, deeply furrowed, and sometimes almost black.
Distribution. Valley of the St. Lawrence River in the neighborhood of Montreal, Quebec, southward to the valley of Cold River, New Hampshire, through western Vermont and Massachusetts and northwestern Connecticut (near Salisbury, Litchfield County), and westward through northern and western New York, southern Ontario, Ohio, the southern peninsula of Michigan, Indiana, Illinois, and Iowa to southeastern Minnesota, northeastern South Dakota, western and southern Missouri, eastern Kansas, and southward through western Pennsylvania, West Virginia and eastern Kentucky; comparatively rare near Montreal and in New England, more abundant farther west; almost entirely replacing Acer saccharum in Iowa, and the only Sugar Maple of South Dakota; easily distinguished in summer by its heavy drooping leaves, and at all seasons of the year by the orange color of the branchlets; the var. Palmeri in a single grove at Tunnel Hill, Johnson County, Illinois; southern Indiana (Shelby, Putnam and Lawrence Counties), and in Clark, Jackson and Dunklin Counties, Missouri; rare and local.
Occasionally planted in the region where it grows naturally as a shade-tree.
10. Acer leucoderme Small. Sugar Maple.
Leaves usually truncate or slightly cordate at base, more or less deeply divided into 3—5 acute caudate-acuminate lobes coarsely and sinuately dentate or undulate, when they unfold coated below with long matted pale caducous hairs, and at maturity thin, dark yellow-green above, bright yellow-green and pilose-pubescent below, 2′—3½′ in diameter; often turning in the autumn bright scarlet on the upper surface before falling; petioles slender, glabrous, 1′—1½′ in length. Flowers yellow, about ⅛′ long, on slender, glabrous pedicels, in nearly sessile clusters; calyx campanulate, glabrous or slightly villose, with rounded ciliate lobes; corolla 0; stamens 7 or 8; filaments villose, longer than the calyx, much shorter than the calyx in the pistillate flower; ovary villose; style elongated, with short spreading lobes. Fruit villose, with long scattered pale hairs until nearly grown, becoming glabrous at maturity, the wings wide-spreading or divergent, ½′—¾′ long; seeds smooth, light red-brown, about ¼′ long.
A tree, usually 20°—25° high, with a trunk a foot in diameter, occasionally 40° high, with a trunk 18′—20′ in diameter, short slender branches forming a rather compact round-topped head, and slender glabrous branchlets dark green when they first appear, becoming bright red-brown and lustrous during their first summer, and marked by numerous small oblong pale lenticels, gradually growing darker in their second year and finally light gray-green. Winter-buds ovoid, acute, dark brown, glabrous, rather more than 1/16′ long, the inner scales becoming bright crimson and very conspicuous when the tree is in flower. Bark of young stems and large branches close, light gray or grayish brown, becoming near the base of old trees dark brown or often nearly black and broken by deep furrows into narrow ridges covered by closely appressed scales.
Distribution. Banks of streams, rocky gorges, and woods in moist soil; valley of the Yadkin River, Stanley County, North Carolina; southeastern Tennessee (Polk County); valley of the Savannah River (Abbeville County, South Carolina, and Richmond County, Georgia) to central and northwestern Georgia (near Rome, Floyd County, and Walker County) and to the valley of the Chattahoochee River to Muscogee County; northern and central Alabama; western Louisiana (Natchitoches and Sabine Parishes); southern Arkansas (Baker Springs, Howard County); rare and local; most abundant in northwestern and central Georgia and northern Alabama.
Occasionally planted as a street tree in the towns of northern Georgia and Alabama; hardy as far north as eastern Massachusetts.
11. Acer saccharinum L. Silver Maple. Soft Maple.
Leaves truncate or somewhat cordate at base, deeply 5-lobed by narrow sinuses, with acute irregularly and remotely dentate lobes, the middle lobe often 3-lobed, 6′—7′ long and nearly as broad, thin, bright pale green above, silvery white and at first slightly hairy below, especially in the axils of the primary veins; turning pale yellow in the autumn before falling; petioles slender, drooping, bright red, 4′—5′ in length. Flowers greenish yellow, opening during the first warm days of the late winter or early spring long before the appearance of the leaves, on short pedicels, in sessile axillary fascicles on shoots of the previous year, or on short spur-like branchlets developed the year before from wood of the preceding season, the staminate and pistillate in separate clusters, on the same or on different trees, and produced from clustered obtuse buds covered with thick ovate pubescent red and green scales ciliate on the margins with a thick fringe of long rufous hairs; calyx slightly 5-lobed, more or less pubescent on the outer surface, long and narrow in the staminate and short and broad in the pistillate flower; corolla 0; stamens 3—7, with slender filaments, three times as long as the calyx of the staminate flower and about as long as the calyx of the pistillate flower; ovary covered, like the young fruit, with a thick coat of pubescence, rudimentary in the sterile flower; styles united at base only, with long exserted stigmatic lobes. Fruit ripening in April and May when the leaves are nearly grown, on slender drooping pedicels, 1½′—2′ long, glabrous, 1½′ to nearly 3′ long, with thin almost straight conspicuously falcate divergent wings sometimes ¾′ broad, prominently reticulate-veined and pale chestnut-brown or rarely bright red; seeds ½′ long, with a pale reddish brown wrinkled coat, germinating as soon as they fall to the ground, and producing plants with several pairs of leaves before the end of the summer.
A tree, 90°—120° high, with a trunk 3°—4° in diameter, generally dividing 10°—15° from the ground into 3 or 4 stout upright secondary stems destitute of branches for a considerable length, brittle pendulous branchlets light green and covered with lenticels when they first appear, soon becoming darker, bright chestnut-brown, smooth and lustrous in the autumn and winter of their first year, and in their second season pale rose color or gray faintly tinged with red. Winter-buds ⅛′ long, with thick ovate bright red outer scales rounded on the back, minutely apiculate, and ciliate on the margins, and acute inner scales pubescent on the inner surface, becoming pale green or yellow and about 1′ long. Bark of young stems and large branches smooth and gray faintly tinged with red, becoming on old trunks ½′—¾′ thick, reddish brown and more or less furrowed, the surface separating into large thin scales. Wood hard, strong, close-grained, easily worked, rather brittle, pale brown, with thick sapwood of 40—50 layers of annual growth; now sometimes used for flooring and in the manufacture of furniture. Sugar is occasionally made from the sap.
Distribution. Sandy banks of streams, rarely in deep often submerged swamps; valley of the St. John’s River (near Fredericton), New Brunswick, to that of the St. Lawrence in Quebec, and southward through western Vermont and central Massachusetts to western Florida, Alabama, and south central Mississippi, and westward through Ontario, New York, Ohio, the southern peninsula of Michigan and southern Indiana to Minnesota, southeastern South Dakota, and eastern Nebraska, and through Kentucky, Tennessee, Missouri, eastern Kansas, northwestern Arkansas, and eastern Oklahoma; in western Louisiana (swamp near Alexandria, Rapides Parish); rare in the immediate neighborhood of the Atlantic coast and on the high Appalachian Mountains; probably of its largest size in the valley of the lower Ohio River.
Often cultivated with several forms differing in habit and in the lobing of the leaves; fast-growing, and largely planted in the eastern states as a park and street tree.
12. Acer rubrum L. Red Maple. Scarlet Maple.
Leaves truncate, more or less cordate by a broad shallow sinus, rounded or cuneate at base, 3—5-lobed by acute sinuses, with irregularly doubly serrate or toothed lobes, the middle lobe often longer than the others, when they unfold pubescent especially beneath, and at maturity light green and glabrous on the upper surface and white or glaucescent and more or less pubescent or densely tomentose (var. tomentosum Kirch. [var. rubrocarpum Detmars]) on the lower surface, particularly along the principal veins, chartaceous or sometimes almost coriaceous, 1½′—6′ long and rather longer than broad; turning in the early autumn to brilliant shades of scarlet and orange, or clear bright yellow; petioles slender, glabrous or puberulous, red or green, 2′—4′ in length. Flowers opening in March and April before the appearance of the leaves, bright scarlet, dull yellowish red or sometimes yellow (var. pallidiflorum Pax.), on long slender pedicels, in few-flowered fascicles on branches of the previous year, from clustered obtuse buds, the staminate and pistillate flowers in separate clusters on the same or on different trees; sepals oblong, obtuse, as long as and broader than the oblong or linear petals; stamens 5—8, scarlet or yellow, with slender filaments exserted in the staminate and included in the pistillate flower; ovary glabrous on a narrow slightly lobed glandular disk; styles slightly united above the base, with long exserted stigmatic lobes. Fruit ripening in the spring or early summer on drooping stems 3′—4′ long, scarlet, dark red or brown or yellow, with thin erect wings, convergent at first, divergent at maturity, ½′—1′ long and ¼′—½′ wide; seeds dark red, with a rugose coat, ¼′ long, germinating as soon as it falls to the ground.
A tree, 80°—120° high, with a tall trunk 3°—4½° in diameter, upright branches usually forming a rather narrow head, and branchlets green or dark red when they first appear, becoming dark or bright red and lustrous at the end of their first summer and marked by numerous longitudinal white lenticels, and gray faintly tinged with red in their second year. Winter-buds obtuse, ⅛′ long, with thick dark red outer scales, rounded on the back and ciliate on the margins, and inner scales becoming ¾′—1′ long, narrow-oblong, rounded at apex and bright scarlet. Bark of young stems and of the branches smooth and light gray, becoming on old trunks ¼′—½′ thick, dark gray, and divided by longitudinal ridges separating on the surface into large plate-like scales. Wood very heavy, close-grained, not strong, light brown often slightly tinged with red, with thick rather lighter colored sapwood; used in large quantities in the manufacture of chairs and other furniture, in turnery, for wooden ware and gun-stocks.
Distribution. Borders of streams, wet swamps, upland forests and rarely on dry rocky hillsides and sand dunes; Newfoundland, southward to southern Florida (banks of the Miami River, Dade County, on the east coast and to Cypress swamps east of Everglade, Lee County, on the west coast) and westward through Quebec to latitude 49° north, and Ontario to the sandy shores of the Upper Peninsula of Michigan (Brevort, Mackinac County, on Lake Michigan and White Fish Point, Chippewa County, on Lake Superior), western Wisconsin, northwestern Minnesota (Buckeye County), southeastern Iowa (Johnson County), central Oklahoma, and the valley of the Trinity River, Texas; on the mountains of North Carolina to altitudes of 4500°; one of the commonest and most generally distributed trees of eastern North America, ranging between more degrees of latitude than any other American tree; most abundant southward especially in the valley of the Mississippi River, and of its largest size in the river swamps of the lower Ohio and its tributaries; in the north often covering with small trees low wet swamps; on the sand dunes and ridges of northern Michigan reduced to a low shrub. On var. tomentosum leaves usually 5-lobed, cordate or rarely rounded at base, with glabrous or pubescent petioles and branchlets; widely distributed but rare; near Cranberry Island, Buckeye Lake, Licking County, Ohio; Biltmore, Buncombe County, North Carolina; neighborhood of Augusta, Richmond County, Georgia; top of Flagstaff Mountain, Barclay, Talladega County, Alabama; Panther Burn, Sharkey County, Mississippi; near Little Rock, Pulaski County, Arkansas; near Page, Leflore County, Oklahoma, and Larissa, Cherokee County, Texas; connected by trees of this variety with pubescent branchlets and winter-buds, and broad-ovate 3—5-lobed slightly cordate leaves and pubescent petioles with
Acer rubrum var. Drummondii Sarg.
Leaves often broader than long, usually 5-lobed, cordate or truncate at base, 3′—6′ long and wide, with a stout midrib and veins, until nearly fully grown covered above with scattered hairs and clothed below with thick snow-white tomentum, and more or less pubescent during the season; petioles stout, hoary-tomentose, 1¼′—4′ in length, becoming nearly glabrous in the autumn. Flowers bright scarlet. Fruit ripening with or before the unfolding of the leaves late in March or in April, bright scarlet, with convergent wings 1¼′—2½′ long and ½′—¾′ wide.
A tree, usually not more than 30°—35° high, with small erect branches forming a narrow head and slender branchlets coated when they first appear with matted pale hairs, becoming glabrous and dark reddish brown in their second season.
Distribution. Deep swamps, eastern Louisiana to the valley of the Neches River (Beaumont, Jefferson County, and Concord, Hardin County), eastern Texas and northward through southern and eastern Arkansas to western Mississippi, western Tennessee and Kentucky, southeastern Missouri (Butler, Stoddard, Dunklin and Mississippi Counties), southern Illinois (Gallatin, Pulaski and Richland Counties), and southwestern Indiana (swamp eighteen miles west of Decker, Knox County, C. C. Deam). A form growing at Hattiesburg, Forrest County, Mississippi, at Glen Gordon, Covington, St. Tammany Parish, and Chopin, Natchitoches Parish, Louisiana, near Beaumont, Jefferson County, Texas, and at Poplar Bluff, Butler County, Missouri, with 3-lobed leaves rounded at base (f. rotundatum Sarg.) shows in the shape of the leaves a transition from the var. Drummondii to
Acer rubrum var. tridens Wood. Red Maple.
Acer carolinianum Britt., not Walt.
Leaves obovate, usually narrowed from above the middle to the rounded or rarely cuneate base, 3-lobed at apex, with acute or acuminate erect or slightly spreading lobes, simple or furnished with short lateral secondary lobes, remotely serrate except toward the base, with incurved glandular teeth, and often ovate by the suppression of the lateral lobes and acute or acuminate, thick and firm in texture, glaucous and usually pubescent or rarely tomentose or tomentulose below, 2′—3′ long and 1½′—2½′ wide; petioles slender, glabrous or pubescent. Flowers sometimes tawny yellow. Fruit usually much smaller and rarely also yellow.
Distribution. Usually with the species; Massachusetts and central New York, southward usually in the coast region and the middle districts to western Florida, along the Gulf coast to the valley of the Trinity River, Texas, and through western Louisiana, and Arkansas to northeastern Mississippi, southern Missouri, western Tennessee and Kentucky and southern Illinois; in North Carolina occasionally ascending on the Appalachian Mountains to altitudes of 3000°; often the prevailing Red Maple in southern Missouri and northwestern Louisiana; in the swamps of western Florida and southwestern Georgia the form with leaves densely tomentose below and pubescent petioles prevails.
13. Acer Negundo L. Box Elder. Ash-leaved Maple.
Leaves usually 3, rarely 5—7-foliolate, with a slender glabrous petiole 2′—3′ in length, the enlarged base often furnished with a minute rim of deciduous white hairs, and in falling leaving a large conspicuous scar surrounding the stem; leaflets ovate to elliptic or obovate, acuminate, and often long-pointed at apex, rounded or cuneate and often unsymmetrical at base, coarsely and irregularly serrate usually only above the middle or nearly entire, and occasionally slightly and irregularly lobulate; when they unfold more or less hoary-tomentose below and slightly pubescent above, and at maturity thin, light green, paler on the lower than on the upper surface, glabrous above, villose-pubescent along the under side of the midrib and veins, often furnished with conspicuous tufts of axillary hairs, otherwise glabrous or slightly pubescent below, 2½′—4′ long, and 1½′—2½′ wide, on slender glabrous petiolules, that of the terminal leaflet ¾′—1′ long and much longer than those of the smaller lateral leaflets. Flowers on slender glabrous or rarely hairy pedicels, minute, apetalous, yellow-green, the staminate and pistillate on separate trees, expanding just before or with the leaves from buds developed in the axils of the last leaves of the previous year, the staminate fascicled, the pistillate in narrow drooping racemes, sometimes furnished near the base with one or two smaller 3-lobed or rarely elliptic leaves; calyx 5-lobed, hairy, campanulate in the staminate flower, much smaller in the pistillate flower and divided to the base into 5 narrow sepals; corolla 0; stamens 4—6, with slender exserted hairy filaments and long linear anthers narrowed and apiculate at apex, 0 in the pistillate flower; ovary on a narrow rudimentary disk, pubescent, only partly inclosed by the calyx; style separating from the base into 2 long stigmatic lobes. Fruit attaining nearly its full size in summer, pendent on glabrous stems 1′—2′ long, in graceful racemes 6′—8′ in length, ripening in the autumn, deciduous from the stems persistent on the branches until the following spring, 1½′—2′ long, with narrow acute pubescent nutlets diverging at an acute angle and constricted below into a stipe-like base, and thin reticulate straight or falcate wings undulate toward the apex; seeds narrowed at the ends, smooth, bright red-brown, ½′ long.
A tree 50°—70° high, with a trunk 2°—4° in diameter, dividing near the ground into a number of stout wide-spreading or erect branches, and slender pale green lustrous glabrous branchlets. Winter-buds terminal acute, ⅛′ long, rather longer than the obtuse lateral buds, the scales tomentose, those of the inner pairs accrescent, becoming 1′ long at maturity, deciduous, leaving conspicuous scars visible at the base of the branchlet for two or three years. Bark of the trunk ¼′—½′ thick, pale gray or light brown and deeply divided into broad rounded ridges separating on the surface into short thick scales. Wood light, soft, close-grained, not strong, creamy white, with thick hardly distinguishable sapwood; occasionally manufactured into cheap furniture, and sometimes used for the interior finish of houses, for wooden ware, cooperage, and paper pulp. Small quantities of maple sugar are occasionally made from this tree.
Distribution. Banks of streams and lakes, and the borders of swamps; western Vermont, western Massachusetts and Connecticut, central New York and southwestern Ontario, and southward to west-central Florida (Hernando County) and westward to Minnesota, Iowa, Nebraska, Missouri, eastern Kansas, Arkansas, eastern Oklahoma, western Louisiana, and eastern and southern Texas to the valley of the lower Rio Blanco.
Often planted in the United States, especially in the western states and in eastern Canada, and in western and northern Europe, especially the varieties with variegated leaves.
Passing into the following varieties:
Var. violaceum Kirch., with slender pale or bluish violet glabrous branchlets covered with a glaucous bloom and rather larger winter-buds. Leaves 3—11, usually 3—7-foliolulate, the leaflets slightly thicker, lanceolate to oblong-ovate or obovate, often entire or irregularly dentate, occasionally lobed, the terminal leaflet sometimes 3-lobed, usually pubescent and furnished with tufts of axillary hairs on the lower surface. Fruit glabrous, usually constricted at the base. Western Massachusetts through Ohio to northern Wisconsin, Minnesota, Iowa and South Dakota, and to northern and southwestern Missouri; in Nez Perces County, Idaho.
Var. texanum Pax., with branchlets covered with pale tomentum. Leaves 3-foliate, the leaflets ovate, or the terminal obovate, acuminate, short-pointed at apex, rounded or cuneate at base, coarsely serrate above the middle or entire, only slightly and irregularly lobed, early in the season villose along the midrib and veins above and thickly coated below with matted pale hairs, and at maturity nearly glabrous on the upper surface and covered below with loose pubescence, 3′—4′ long and 2′—3′ wide. Fruit puberulous, constricted into a short stipe-like base. Western and southwestern Missouri, southeastern Kansas, Arkansas, Oklahoma and eastern Texas to the valley of the San Antonio River. Passing into forma latifolia Sarg. differing only in its glabrous branchlets, and distributed from eastern Texas through Louisiana to western Mississippi, western North Carolina, Virginia and southern Ohio.
Var. interior Sarg., with branchlets covered with close pale pubescence, or rarely nearly glabrous. Leaves trifoliate, with puberulous petioles, rachis and petiolules, the long-stalked leaflets ovate to lanceolate, or the terminal sometimes obovate, acuminate and long-pointed at apex, cuneate, rounded or cordate at base, coarsely serrate, sometimes distinctly 3-lobed at base, glabrous or villose on the midrib below, or in Arizona sometimes sparingly pubescent on the lower surface, 3′—4′ long and 1½′—4′ wide. Fruit glabrous, not at all, slightly or at the north conspicuously constricted at the base. Southern Manitoba, Saskatchewan and Alberta to Wyoming, and through the mountain regions of Colorado and Utah to New Mexico and Arizona.
Var. arizonicum Sarg., with glabrous branchlets thickly covered with a glaucous bloom. Leaves thin, 3-foliolulate; petioles slender, glabrous, 1¾′—3′ long, often turning bright red late in summer; leaflets oblong-ovate to rhombic, acuminate and long-pointed at apex, rounded or cuneate at base, coarsely serrate, often slightly lobed near the middle, glabrous with the exception of conspicuous tufts of axillary hairs, 2½′—4′ long, 1½′—2′ wide; petiolules slender, glabrous, usually bright red, that of the terminal leaflet ¾′—1′ long, the others not more than ⅛′ in length. Fruit in glabrous racemes 3′ or 4′ long, the body glabrous, spreading, not constricted at base. A tree, 20°—25° high. Bark fissured. Mountain cañons, central and southern Arizona up to 8000° altitude, and in Socorro County, New Mexico. More distinct is
Acer Negundo var. californicum Sarg.
Leaves trifoliate with tomentose or nearly glabrous rachis and petiolules; leaflets oblong-ovate to rhombic, acuminate and long-pointed at apex, cuneate or unsymmetrically rounded at base, coarsely serrate above the middle, or nearly entire, when they unfold hoary-tomentose below and densely pubescent above, occasionally deeply lobed, glabrous on the upper surface except along the midrib and veins, thickly coated on the lower surface with matted pale hairs and furnished with large axillary tufts. Fruit on pubescent pedicels, puberulous or nearly glabrous, not constricted or rarely slightly constricted at base.
A tree, 20°—50° high, with dark bark, hoary-tomentose branchlets and winter-buds.
Distribution. California, valley of the lower Sacramento River and the interior valleys of the coast ranges from the Bay of San Francisco to Santa Barbara County and in elevated cañons on the western slopes of the San Bernardino Mountains; widely distributed but nowhere abundant.
Occasionally planted in California.
XXXVI. HIPPOCASTANACEÆ.
Trees or rarely shrubs, with stout terete branchlets conspicuously marked by triangular leaf-scars, fetid bark, thick fleshy roots, and large scaly winter-buds, the inner scales accrescent with the young shoots and often brightly colored. Leaves opposite, digitately compound, without stipules, deciduous; leaflets 3—9, lanceolate or ovate, serrate, pinnately veined. Flowers polygamo-monœcious, showy, white, red, or pale yellow, on stout jointed pedicels from the axils of minute caducous bracts, racemose or nearly unilateral on the branches of large terminal thyrsi or panicles, appearing later than the leaves, only those near the base of the branches of the inflorescence perfect and fertile; calyx 5 or rarely 2-lobed, the lobes imbricated in the bud, unequal, campanulate or tubular, the lobes imbricated in the bud, mostly oblique or posteriorly gibbous at base; disk hypogynous, annular, depressed, lobed, more or less gibbous posteriorly; petals 4 or 5, imbricated in the bud, alternate with the lobes of the calyx, deciduous, the anterior petal often abortive, unguiculate, the margins of the claw commonly involute; stamens 6—8, rarely 5, generally 7, inserted on the disk, free, unequal; filaments filiform; anthers ellipsoid, glandular-apiculate, attached on the back below the middle, introrse, 2-celled, the contiguous cells opening longitudinally; ovary sessile, oblong or lanceolate, 3-celled, echinate or glabrous, rudimentary in the staminate flower; style slender, elongated, generally more or less curved; stigma terminal, entire, mostly acute; ovules 2 in each cell, borne on the middle of its inner angle, amphitropous, the upper ascending, the micropyle inferior, the lower pendulous, the micropyle superior. Fruit an echinate or smooth coriaceous capsule, 3-celled and loculicidally 3-valved, the cells 1-seeded by abortion, often by suppression 1 or 2-celled, and then 1 or 2-seeded, the remnants of the abortive cells and seeds commonly visible at its maturity. Seeds without albumen, round when one is developed, or, when more than one, flattened by mutual pressure; seed-coat coriaceous, dark chestnut-brown or pale orange-brown, smooth and lustrous, with a broad opaque light-colored hilum; embryo filling the cavity of the seed; cotyledons very thick and fleshy, often conferruminate, unequal, incurved on the short conic radicle, remaining under ground in germination; plumule conspicuously 2-leaved.
The Horsechestnut family is composed of the widely distributed genus Aesculus and of Billia Peyr., a genus of two species of Mexican and Central American trees, differing from Aesculus in its 3-foliolate leaves.
1. AESCULUS L.
Characters of the family; leaves 5—9-foliolate.
Aesculus with fifteen or sixteen species, is represented in the floras of the three continents of the northern hemisphere and is most abundant in the southeastern United States. It produces soft straight-grained light-colored wood and bitter and astringent bark. The seeds contain a bitter principle, aesculin. Aesculus Hippocastanum L., of the mountains of Greece, the common Horsechestnut of gardens, is largely planted as an ornamental tree in all countries with temperate climates, and now occasionally grows spontaneously in the eastern states.
The generic name is the classical name of an Oak-tree.
CONSPECTUS OF THE ARBORESCENT SPECIES OF NORTH AMERICA.
- Winter-buds without a resinous covering. Pavia.
- Calyx campanulate (occasionally tubular in 3); margins of the petals ciliate, eglandular; flowers usually yellow. Octandræ.
- Fruit covered with prickles; flowers yellow; petals nearly equal in length, shorter than the stamens.
- 1. A. glabra (A, C).
- Fruit without prickles; flowers yellow or red; petals unequal in length, longer than the stamens.
- Pedicels and calyx glandular-villose.
- 2. A. octandra (A, C).
- Pedicels and calyx without glandular hairs.
- 3. A. georgiana (C).
- Calyx tubular; margins of the unequal petals without hairs, glandular; fruit without prickles. Eupaviæ.
- Lower surface of the leaves glabrous or slightly pubescent along the midrib; flowers red; seeds dark chestnut-brown.
- 4. A. Pavia (C).
- Lower surface of the leaves tomentose or pubescent; flowers red and yellow, red, or in one form yellow; seed light yellow-brown.
- 5. A. discolor (C).
- Winter-buds resinous; petals nearly equal in length, shorter than the stamens; fruit without prickles. Calothyrsus.
- 6. A. californica (G).
1. Aesculus glabra Willd. Ohio Buckeye. Fetid Buckeye.
Leaves with a slender petiole 4′—6′ long and enlarged at the end, a rachis often furnished on the upper side with clusters of dark brown chaff-like scales surrounding the base of the petiolules, and 5 rarely 7 (var. Buckleyi Sarg.) oval-oblong or obovate acuminate leaflets gradually narrowed to the elongated entire base, finely and unequally serrate above, at first sessile, becoming slightly petiolulate at maturity, covered on the lower surface like the petioles when they first appear with floccose deciduous hairs most abundant on the midrib and veins, and at maturity glabrous with the exception of a few hairs along the under side of the conspicuous yellow midrib and in the axils of the principal veins, or rarely covered below with close dense pubescence persistent during the season (var. pallida, Kirch.); yellow-green, paler on the lower than on the upper surface, 4′—6′ long and 1½′—2½′ wide; turning yellow in the autumn before falling. Flowers pale yellow-green, mostly unilateral, ½′—1½′ long or more than twice as long as the pedicels, appearing in April and May in clusters 5′—6′ long and 2′—3′ wide, and more or less densely covered with pubescence, with short usually 4—6-flowered branches; calyx campanulate; petals nearly equal, puberulous, the thin limb about twice as long as the claw, in the lateral pair broad-ovate or oblong, and in the superior pair oblong-spatulate, much narrower, sometimes marked with red stripes; stamens usually 7, with long exserted curved pubescent filaments and orange-colored slightly hairy anthers; ovary pubescent, covered with long slender deciduous prickles thickened and tubercle-like at base. Fruit on a stout stem ½′—1′ long, ovoid or irregularly obovoid, pale brown, 1′—2′ long, with thin or sometimes thick valves, roughened by the enlarged persistent bases of the prickles of the ovary; seeds 1′—1½′ broad.
A tree, occasionally 70° high, with a trunk rarely 2° in diameter, small spreading branches, and branchlets orange-brown and covered at first with short fine pubescence, soon glabrous, reddish brown, and marked by scattered orange-colored lenticels; usually much smaller, and rarely more than 30° high. Winter-buds ⅔′ long, acuminate, with thin nearly triangular pale brown scales, the outer bright red on the inner surface toward the base, those of the inner pair strap-shaped, prominently keeled on the back, minutely apiculate and slightly ciliate along the margins, and at maturity 1½′—2′ long and bright yellow. Bark of young stems and of the branches dark brown and scaly, becoming on old trees ¾′ thick, ashy gray, densely furrowed, and broken into thick plates roughened on the surface by numerous small scales. Wood light, soft, close-grained, not strong, often blemished by dark lines of decay, nearly white, with thin dark-colored sapwood of 10—12 layers of annual growth; used in the manufacture of artificial limbs, wooden ware, wooden hats, and paper pulp; occasionally sawed into lumber. An extract of the bark has been used as an irritant of the cerebro-spinal system.
Distribution. River-bottoms and the banks of streams in rich moist soil; western slopes of the Alleghany Mountains, western and southwestern Pennsylvania to northern Alabama, and westward to central and southern Iowa, southeastern Nebraska, northern and central Missouri and northeastern Kansas; nowhere abundant; most common and of its largest size in the valley of the Tennessee River in Tennessee and northern Alabama.
A shrubby form (var. micrantha Sarg.) with flowers not more than ½′ long near Fulton, Hempstead County, Arkansas. In southern Missouri, Arkansas and probably Oklahoma Aesculus glabra is replaced by the var. leucodermis Sarg. with glabrous leaves pale green or glaucescent below. A tree occasionally 60° high, well distinguished from the type by the smooth pale nearly white bark of the trunk and large branches, becoming on old trunks light brown and separating into oblong flakes, and by its later flowers; the var. pallida in Iowa, Missouri and Arkansas; the var. Buckleyi in Jackson County, Missouri, eastern Kansas, Ohio and Mississippi.
The Ohio Buckeye is occasionally cultivated as an ornamental plant in the eastern United States and Europe; hardy as far north as eastern Massachusetts.
× Aesculus Bushii Schn., probably a hybrid of Aesculus discolor var. mollis Sarg. and Aesculus glabra var. leucodermis Sarg., has been found in the neighborhood of Fulton, Hempstead County, Arkansas; and what is evidently a hybrid of Aesculus discolor var. mollis and the typical form of Aesculus glabra occurs near Starkville, Oktibbeha County, Mississippi.
× Aesculus mississippiensis Sarg., a probable hybrid between Aesculus glabra and Aesculus Pavia with characters intermediate between those of its supposed parents, occurs near Brookville, Noxubee County, Mississippi. The mingling of a species of the Octandræ and of the Eupaviæ in these hybrids of Aesculus is shown by the presence of both hairs and glands on the margins of the petals.
2. Aesculus octandra Marsh. Sweet Buckeye.
Leaves with slender or slightly pubescent petioles 4′—6′ long, and 5—7 elliptic or obovate-oblong leaflets, acuminate and usually abruptly long-pointed at apex, gradually narrowed and cuneate at base, sharply and equally serrate, glabrous above except on the midrib and veins sometimes clothed with reddish brown pubescence, when they unfold more or less canescent-pubescent on the lower surface, becoming glabrous at maturity, with the exception of a few pale or rufous hairs along the stout midrib and in the axils of the principal veins, dark yellow-green, duller on the lower than on the upper surface, 4′—6′ long, and 1½′—2½′ wide; petiolules 1/12′—½′ in length; turning yellow in the autumn before falling. Flowers opening in early spring when the leaves are about half grown, 1′—1½′ long, pale or dark yellow, rarely red, pink or cream-colored (var. virginica Sarg.), on short glandular-villose pedicels mostly unilateral on the branches of the pubescent clusters 5′—7′ in length; calyx campanulate, glandular-villose; petals connivent, very unequal, puberulent, the claws villose within, limb of the superior pair spatulate, minute, the long claws exceeding the lobes of the calyx, those of the lateral pair obovate or nearly round and subcordate at base; stamens usually 7, rather shorter than the petals, with straight or inclining subulate villose filaments; ovary pubescent. Fruit 2′—3′ long, generally 2-seeded, with thin smooth or slightly pitted pale brown valves; seeds 1½′ to nearly 2′ wide.
A tree, sometimes 90° high, with a tall straight trunk 2½°—3° in diameter, small rather pendulous branches, and glabrous or nearly glabrous branchlets orange-brown when they first appear, becoming in their second year pale brown and marked by numerous irregularly developed lenticels. Winter-buds ⅔′ long, rather obtuse, with broad-ovate pale brown outer scales rounded on the back, minutely apiculate, ciliate, and slightly covered with a glaucous bloom, the inner scales becoming sometimes 2′ long, bright yellow or occasionally scarlet. Bark of the trunk about ¾′ thick, dark brown, divided by shallow fissures and separating on the surface into small thin scales. Wood light, soft, close-grained, difficult to split, creamy white, with thick hardly distinguishable sapwood; used in the manufacture of artificial limbs, for wooden ware, wooden hats, paper pulp, and occasionally sawed into lumber.
Distribution. Rich river-bottoms and mountain slopes; southwestern Pennsylvania (Alleghany, Greene and Fayette Counties), southward along the mountains to east Tennessee, and northwestern Georgia, and westward to north central Ohio (near Plymouth, Richard County), southeastern and southern Indiana (near Aurora, Dearborn County, and on the banks of Dry River near Leavenworth, Crawford County, C. C. Deam) and to southern Illinois (near Golconda, Pope County, shrub 6′—12′ high, E. J. Palmer); the var. virginica at White Sulphur Springs, West Virginia.
Occasionally cultivated in the parks of the eastern United States and Europe.
× Aesculus hybrida DC., with red and yellow flowers, believed to be a hybrid of Aesculus octandra and Aesculus Pavia, appeared in the Botanic Garden at Montpelier in France early in the nineteenth century, and in many varieties is cultivated in Europe and occasionally in the eastern United States.