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.
3. [Aesculus georgiana] Sarg.
Leaves with slender glabrous petioles 4½′—6′ in length, and 5 leaflets oblong-obovate, abruptly acuminate and long-pointed at apex, gradually narrowed and acuminate at base, finely often doubly serrate with rounded teeth pointing forward, sparingly covered early in the season, especially on the upper side of the midrib and veins, with short caducous hairs, yellow-green above, green, glabrous and lustrous or pubescent (var. pubescens Sarg.) below, 4½′—6′ long, 1½′—2½′ wide, with a stout orange-colored midrib and 20—30 pairs of slender primary veins; petiolules stout, puberulous early in the season, ¼′—½′ in length. Flowers opening in April and May 1′—1⅛′ long, on slender puberulous pedicels, in broad pubescent panicles, 4′—6′ in length; calyx campanulate or tubular, puberulous, about 5/12′ in diameter, red on the upper side, pale yellow on the lower side or entirely red or yellow, 5-lobed, the lobes oblong-ovate, narrowed and rounded at apex, finely serrate on the margins; petals connivent, obovate, rounded at apex, gradually narrowed below, those of the superior and lateral pairs very unequal in size, puberulous and glandular on the outer surface, pubescent on the inner surface, ciliate on the margins, bright yellow or red, their claws furnished on the margins with long white hairs, those of the superior pair as long as the lateral petals; stamens 7, shorter than the petals; filaments villose, especially below the middle; ovary covered with matted pale hairs; styles exserted, villose. Fruit on stout pendulous pedicels, globose, usually 1-seeded, 1′—1¼′ in diameter, with thin light brown slightly pitted valves; seed globose, dark chestnut-brown.
A tree, 25°—30° high, with a trunk 6′—10′ in diameter, slender erect and spreading branches and stout glabrous branchlets, orange-green and marked by pale lenticels when they first appear, becoming light reddish brown in their first winter; more often a large or small round-topped shrub 3°—5° tall and broad. Bark of the trunk thin, dark brown, the surface separating into small thin scales. Winter-buds about ⅓′ long, with light reddish brown scales, narrowed, rounded and short-pointed at apex. The common Buckeye of the Piedmont region of North and South Carolina and northern Georgia.
Distribution. Central North Carolina (Durham and Orange Counties), southward to eastern (Richmond County) and central Georgia; northern Alabama (Madison, Etowah and Tuscaloosa Counties), and near Pensacola, Escambia County, Florida. The var. pubescens occasionally arborescent in habit, common in the woods west of Augusta, Richmond County, and in De Kalb, Rabun and Floyd Counties, Georgia, ranging northward to Orange County, North Carolina, and ascending on the Blue Ridge to altitudes of 3000°; in northern Alabama.
× Aesculus Harbisonii Sarg., a probable hybrid between A. discolor var. mollis and A. georgiana, has appeared in the Arnold Arboretum among plants of A. georgiana raised from seeds collected near Stone Mountain, De Kalb County, Georgia.
A distinct form of Aesculus georgiana is
Aesculus georgiana var. lanceolata Sarg.
Leaves with glabrous petioles 3½′—5½′ in length, and 5 lanceolate or slightly oblanceolate leaflets long-acuminate at apex, cuneate at base, and finely glandular-serrate, when the flowers open early in May thin yellow-green above, pale below, glabrous with the exception of occasional hairs on the under side of the slender midrib and of minute axillary tufts, 6′—8′ long and 1¼′—1½′ wide; petiolules 1/12′—⅙′ in length. Flowers on stout puberulous pedicels, bright red, in narrow crowded clusters, 8′—10′ long; calyx narrow-campanulate, otherwise as in the type. Fruit not seen.
A tree 25°—30° high, with a short trunk 6′—10′ in diameter, small erect and spreading branches forming a narrow head, and slender glabrous branchlets orange-brown when they first appear, becoming dark gray-brown and marked by pale lenticels in their second year.
Distribution. Georgia, rich woods near Clayton, Rabun County.
4. [Aesculus Pavia] L. Red-flowered Buckeye.
Leaves with slender petioles glabrous or puberulous early in the season and 4′—7′ long, and 5 short-petiolulate, oblong-obovate, acuminate leaflets, gradually narrowed at base, coarsely often doubly serrate above with incurved teeth, slightly pubescent early in the season along the upper side of the midrib and veins, and glabrous or slightly pubescent below, and at maturity thin, lustrous and glabrous, dark green on the upper surface, pale yellow-green on the lower surface, often furnished with conspicuous tufts of axillary hairs, 3½′—6′ long and 1¼′—1¾′ wide, with a thin midrib and from 18—30 pairs of slender primary veins. Flowers in narrow pubescent panicles, 4½′—8′ in length, on slender pubescent pedicels; calyx tubular, dark red, puberulous on both surfaces, minutely lobed, the lobes rounded, much shorter than the light red petals; petals connivent, unequal, oblong-obovate, rounded at apex, glandular on the outer surface and on the margins, gradually narrowed below into a long slender villose claw; claw of the lateral petals about as long or shorter than the calyx, those of the superior pair much longer than the calyx, their blades not more than one-third as large as the blades of the lateral pair; stamens exserted; filaments villose like the ovary. Fruit obovoid or subglobose, light brown, smooth, generally pitted, usually 1 or 2-seeded, pendulous on slender stems; seeds usually about 1′ in diameter, dark chestnut-brown and lustrous with a small hilum.
Occasionally a tree, rarely 40° high, with a tall trunk 8′—10′ in diameter covered with smooth dark bark, large erect branches forming an open head, and stout light orange-brown branchlets marked in their second year by conspicuous emarginate scars of fallen leaves showing the ends of 3 fibro-vascular bundles; usually a shrub, often flowering when not more than 3′ high.
Distribution. Southeastern Virginia, southward to western Florida to the valley of the Suwanee River (near Old Town, Lafayette County), and westward to eastern Louisiana, usually in the neighborhood of the coast; in Alabama ranging inland to Jefferson and Dallas Counties and in Louisiana to West Feliciana Parish; in southern Kentucky (near Bowling Green, Warren County).
5. [Aesculus discolor] Pursh. Buckeye.
Leaves with slender grooved villose or pubescent usually ultimately glabrous petioles 4′ or 5′ long, and 5 oblong-obovate or elliptic leaflets, acuminate and usually long-pointed at apex, gradually narrowed and acuminate at the entire base, finely or coarsely and sometimes doubly crenulate-serrate above, dark green, lustrous and glabrous except along the slender yellow midrib and veins on the upper surface, lighter colored and tomentulose or tomentose on the lower surface, 4′—5′ long, 1½′—2′ wide, nearly sessile or raised on slender petiolules up to ½′ in length. Flowers opening from the first to the middle of April, usually ¾′—1′ long, on slender pubescent pedicels much thickened on the fruit, sometimes ¼′ long, and mostly aggregated toward the end of the short branches of the narrow pubescent inflorescence 6′—8′ in length; calyx red, rose color or yellow more or less deeply tinged with red, tubular, short and broad or elongated, puberulous on the outer surface, tomentose on the inner surface, with rounded lobes; petals yellow, shorter than the stamens, connivent, unequal, oblong-obovate, rounded at apex, puberulous on the outer surface and glandular on the margins with minute dark glands, those of the superior pair about half as wide as those of the lateral pair, with claws much longer than the calyx; filaments and ovary villose. Fruit ripening and falling in October, usually only a few fruits maturing in a cluster, generally obovoid or occasionally subglobose, mostly 2-seeded, 1½′—2½′ long, with very thin, light brown slightly pitted valves; seeds light yellow-brown, sometimes 1½′ in diameter, with a comparatively small hilum and a thin shell.
Rarely arborescent and occasionally 25° high, with a straight trunk 6′ or 7′ in diameter, stout branches forming a narrow symmetric head, and slender branchlets marked by numerous small pale lenticels, green and puberulous at first, becoming gray slightly tinged with red during their first winter and only slightly darker in their second year; usually a small or large shrub. Winter-buds broad-ovoid, obtusely pointed, about ¼′ long, with rounded apiculate light red-brown scales. Bark thin, smooth, and pale.
Distribution. Rich woods; Shell Bluff on the Savannah River, Burke County, Georgia; near Birmingham, Jefferson County, and Selma, Dallas County, Alabama; near Campbell, Dunklin County, Missouri; Comal Springs, New Braunfels County, and Sutherland Springs, Wilson County, Texas; rare and local, and found as a tree only near Birmingham, Alabama; more abundant is the var. mollis Sarg. (Aesculus austrina Small) with bright red flowers; a tree up to 25° or 30° high, or more often a large or small shrub; valley of the lower Cape Fear River (near Wilmington, New Hanover County), North Carolina, southward near the coast to the neighborhood of Charleston, South Carolina, through Georgia to the neighborhood of Rome, Floyd County, and southward to western Florida; in Alabama widely distributed from Jefferson County southward; widely distributed in Mississippi except in the neighborhood of the Gulf coast, to West Feliciana Parish, eastern Louisiana; more common and generally distributed in western Louisiana, and through eastern Texas to the valley of the San Antonio River (neighborhood of San Antonio, Bexar County) and to that of the upper Guadalupe River (near Boerne, Kendall County), ranging northward through Arkansas to southern Missouri and western Tennessee.
On the Edwards Plateau of western Texas Aesculus discolor is represented by the var. flavescens Sarg., with yellow flowers, appearing a few days earlier than those of the var. mollis; a shrub 9′—12′ high, or often much smaller; interesting as the only form of Eupaviæ with yellow flowers; San Marcos, Hays County, common on the slopes above Comal Springs, near New Braunfels, Comal County, near Boerne, Kendall County (with the var. mollis), Kerrville, Kerr County, and Cancan, Uvalde County.
6. [Aesculus californica] Nutt. Buckeye.
Leaves with slender grooved petioles 3′—4′ long, and 4—7 usually 5 oblong-lanceolate acuminate leaflets narrowed and acuminate or rounded at base, sharply serrate, 4′—6′ long, 1½′—2′ wide, dark green above, paler below, slightly pubescent when they first appear, becoming glabrous or nearly so, on petiolules ½′—1′ long; falling early, often by midsummer. Flowers white or pale rose color, 1′—1¼′ long, appearing from May to July when the leaves are fully grown, on short pedicels mostly unilateral on the long branches of the densely flowered long-stemmed pubescent cluster 3′—9′ in length; calyx 2-lobed, slightly toothed, much shorter than the narrow oblong petals; stamens 5—7, with long erect exserted slender filaments and bright orange-colored anthers; ovary densely pubescent. Fruit obovoid, often somewhat gibbous on the outer side, with thin smooth pale brown valves, usually 1-seeded, 2′—3′ long, on a slender stalk ¼′—½′ in length; seeds pale orange-brown, 1½′—2′ broad.
A tree, rarely 20°—30° high, with a short trunk occasionally 4°—5° in diameter, often much enlarged at base, stout wide-spreading branches, forming a round-topped head, and branchlets glabrous and pale reddish brown when they first appear, becoming darker in their second season; more often a shrub, with spreading stems 10°—15° high forming broad dense thickets. Winter-buds acute, covered with narrow dark brown scales rounded on the back and thickly coated with resin. Bark of the trunk about ¼′ thick, smooth, and light gray or nearly white. Wood soft, light, very close-grained, white or faintly tinged with yellow, with thin hardly distinguishable sapwood of 10—12 layers of annual growth.
Distribution. California, borders of streams, valley of the south fork of the Salmon River, Siskiyou County, south along the coast ranges to San Luis Obispo County and on the western slope of the Sierra Nevada, usually at altitudes between 2000° and 2500°, occasionally to 5000°, to the northern slopes of Tejon Pass, Kern County, and to Antelope Valley, Los Angeles County.
Occasionally cultivated as an ornamental plant in the Pacific states, and in western and southern Europe.