1. CORNUS L. Dogwood.
Trees and shrubs, with astringent bark, opposite or rarely alternate deciduous leaves conduplicate or involute in the bud. Flowers small, perfect, white, greenish white or yellow; calyx-tube minutely 4-toothed, the teeth valvate in the bud; disk pulvinate, depressed in the centre, or obsolete; petals 4, valvate in the bud, oblong-ovate, inserted on the margin of the disk; stamens 4, alternate with the petals; filaments slender, exserted; ovary 2-celled; style exserted, simple, columnar, crowned with a single capitate or truncate stigma; raphe dorsal. Fruit ovoid or oblong; flesh thin and succulent; nut bony or crustaceous, 2-celled, 2 or sometimes 1-seeded. Seed compressed; embryo straight or slightly incurved.
Cornus with nearly fifty species is widely distributed through the three continents of the northern hemisphere, and south of the equator is represented in Peru by a single species. Of the sixteen or seventeen species of the United States four are arborescent. Cornus is rich in tannic acid, and the bark and occasionally the leaves and unripe fruit are used as tonics, astringents, and febrifuges. Of exotic species, Cornus mas, L., is often planted in the eastern states as an ornamental tree, and its edible fruit is used in Europe in preserves and cordials. The wood of Cornus is hard, close-grained, and durable, and is used in turnery and for charcoal.
The generic name, from cornu, relates to the hardness of the wood produced by plants of this genus.
CONSPECTUS OF THE ARBORESCENT SPECIES OF THE UNITED STATES.
Flowers greenish, in a dense cymose head surrounded by a conspicuous corolla-like involucre of 4—6 white or rarely red scales, from terminal buds formed the previous summer; fruit ovoid, bright red, rarely yellow. Heads of flower-buds inclosed by the involucre during the winter; involucral scales 4, obcordate or notched at apex; leaves ovate to elliptic.1. [C. florida] (A, C). Heads of flower-buds inclosed only at base by the involucre during the winter; involucral scales 4—6, oblong to obovate, usually acute at apex; leaves ovate or rarely obovate.2. [C. Nuttallii] (B, G). Flowers cream color, in a flat cymose head, without involucral scales, terminal on shoots of the year; fruit subglobose, white or dark blue. Leaves opposite, scabrous above; fruit white.3. [C. asperifolia] (A, C). Leaves mostly alternate and clustered at the end of the branches, smooth above; fruit dark blue or rarely yellow.4. [C. alternifolia] (A, C).
1. [Cornus florida] L. Flowering Dogwood.
Leaves ovate to elliptic or rarely slightly obovate, acute and often contracted into a slender point at apex, gradually narrowed at base, remotely and obscurely crenulate-toothed on the somewhat thickened margins, and mostly clustered at the end of the branches, when they unfold pale and pubescent below and puberulous above, and at maturity thick and firm, bright green and covered with minute appressed hairs on the upper surface, pale or sometimes almost white and more or less pubescent on the lower surface, 3′—6′ long and 1½′—2′ wide, with a prominent light-colored midrib deeply impressed above, and 5 or 6 pairs of primary veins connected by obscure reticulate veinlets; in the autumn turning bright scarlet on the upper surface, remaining pale on the lower surface; petioles grooved, ½′—¾′ in length. Flowers: head of flower-buds appearing during the summer between the upper pair of lateral leaf-buds, inclosed by 4 involucral scales remaining light brown and more or less covered with pale hairs during the winter, and borne on a stout club-shaped puberulous peduncle ¼′ long or less during the winter and becoming 1′—1½′ in length; involucral scales beginning to unfold, enlarge and grow white in early spring and when the flowers open in March at the south to May at the north, when the leaves are nearly fully grown, forming a flat corolla-like cup 3′—4′ in diameter, becoming at maturity obovoid, 1′—1½′ wide, gradually narrowed below the middle and notched at the rounded apex, reticulate-veined, pure white, pink, or rarely bright red, deciduous after the fading of the flowers; flowers in dense many-flowered cymose heads, in the axils of broad-ovate nearly triangular minutely apiculate glabrous light green deciduous bracts, ⅛′ in diameter; calyx terete, slightly urceolate, puberulous, obtusely 4-lobed, light green; corolla-lobes strap-shaped, rounded or acute at apex, slightly thickened on the margins, puberulous on the outer surface, reflexed after anthesis, green tipped with yellow; disk large and orange-colored; style crowned with a truncate stigma. Fruit ripening in October, ovoid, crowned with the remnants of the narrow persistent calyx and with the style, bright scarlet or rarely yellow (f. xanthocarpa Rehd.), lustrous, ½′ long and ¼′ broad, with thin mealy flesh, and a smooth thick-walled slightly grooved stone acute at the ends, and 1 or 2-seeded; seeds oblong, pale brown.
A bushy tree, rarely 40° high, with a short trunk 12′-18′ in diameter, slender spreading or upright branches, and divergent branchlets turning upward near the end, pale green or green tinged with red when they first appear, glabrous or slightly puberulous, bright red or yellow-green during their first winter and nearly surrounded by the narrow ring-like leaf-scars, later becoming light brown or gray tinged with red; frequently toward the northern limits of its range a much-branched shrub. Winter-buds formed in midsummer; the terminal covered by 2 opposite acute pointed scales rounded on the back and joined below for half their length, and accompanied by 2 pairs of lateral buds, each covered by a single scale, those of the lower pair shedding their scales in the autumn and remaining undeveloped. Bark of the trunk ⅛′—¼′ thick, with a dark red-brown surface divided into quadrangular or many-sided plate-like scales. Wood heavy, hard, strong, close-grained, brown sometimes changing to shades of green and red, with lighter colored sapwood of 30—40 layers of annual growth; largely used in turnery, for the bearings of machinery, the hubs of small wheels, barrel-hoops, the handles of tools, and occasionally for engravers’ blocks.
Distribution. Usually under the shade of taller trees in rich well-drained soil; southern Maine to southern Ontario, southern Michigan, southeastern Kansas and eastern Oklahoma, and southward to central Florida and the valley of the Brazos River, Texas; on the mountains of northern Mexico; comparatively rare at the north; one of the commonest and most generally distributed inhabitants of the deciduous-leaved forests of the middle and southern states, ranging from the coast nearly to the summits of the high Alleghany Mountains. Trees with rose-colored or with pink involucral scales occasionally occur (var. rubra André). A variety with pendulous branches is known in gardens (var. pendula Dipp.); the var. xanthocarpa near Oyster Bay, Nassau County, Long Island, New York, and at Saluda, Polk County, North Carolina.
Often planted as an ornament of parks and gardens in the eastern states.
2. [Cornus Nuttallii] Aud. Dogwood.
Leaves ovate or slightly obovate, acute and often contracted into a short point at the apex, cuneate at base, faintly crenulate-serrate, and generally clustered toward the end of the branches, when they unfold coated below with pale tomentum and puberulous above, and at maturity thin, bright green and slightly puberulous, with short appressed hairs on the upper surface, and woolly pubescent on the lower surface, 4′—5′ long and 1½′—3′ wide, with a prominent midrib impressed above, and about 5 pairs of slender primary veins connected by remote reticulate veinlets; in the autumn turning bright orange and scarlet before falling; petioles stout, grooved, pubescent, ½′—⅔′ in length, with a large clasping base. Flowers: head of flower-buds appearing during the summer between the upper pair of lateral leaf-buds, surrounded at base but not inclosed by the involucral scales during the winter, hemispheric, ½′ in diameter, usually nodding on a stout hairy peduncle ¾′—1′ long; involucral scales becoming when the flowers open 1½′—3′ long and 1½′—2′ wide, white or white tinged with pink, oblong to obovate or nearly orbicular, and acute, acuminate, or obtuse, entire and thickened at apex, puberulous on the outer surface, gradually narrowed below the middle and conspicuously 8-ribbed, the spreading ribs united by reticulate veinlets; flowers in dense cymose heads from the axils of minute acuminate scarious deciduous bracts; calyx terete, slightly urceolate, puberulous on the outer surface, yellow-green, or light purple, with dark red-purple lobes; petals strap-shaped, rounded at apex, spreading, somewhat puberulous on the outer surface, with thickened slightly inflexed margins, yellow-green; style crowned with a truncate stigma. Fruit ripening in October, in dense spherical heads of 30—40 drupes surrounded at base by a ring of abortive pendulous ovaries, ½′ long, ovoid, much flattened, crowned with the broad persistent calyx, bright red or orange-colored, with thin mealy flesh, and a thick-walled 1 or 2-seeded stone obtuse at the ends and scarcely grooved; seeds oblong, compressed, with a very thin pale papery coat.
A tree, 40°—60°, or exceptionally 100° high, with a trunk 1°—2° in diameter, small spreading branches forming an oblong conic or ultimately round-topped head, and slender light green branchlets coated while young with pale hairs, becoming glabrous or puberulous, dark reddish purple or sometimes green during their first winter and conspicuously marked by the elevated lunate leaf-scars, ultimately becoming light brown or brown tinged with red. Winter-buds formed in July; the terminal acute, ⅓′ long, covered by 2 narrow-ovate acute long-pointed puberulous light green opposite scales, accompanied by 2 pairs of lateral buds, each covered by a single scale, those of the lower pair shedding their scales in the autumn and remaining undeveloped, those of the upper pair clothed with pale hairs, especially toward the apex, their scales thickening, turning dark purple, lengthening in the spring with the inclosed shoot, finally becoming scarious and developing into small leaves, and in falling marking the base of the branchlets with ring-like scars. Bark of the trunk about ¼′ thick, brown tinged with red, and divided on the surface into small thin appressed scales. Wood heavy, exceedingly hard, strong, close-grained, light brown tinged with red, with lighter colored sapwood of 30—40 layers of annual growth; used in cabinet-making, for mauls and the handles of tools.
Distribution. Usually in moist well-drained soil under the shade of coniferous forests; valley of the lower Fraser River and Vancouver Island, British Columbia, southward through western Washington and Oregon, on the coast ranges of California to the San Bernardino Mountains, and on the western slopes of the Sierra Nevada; southward up to altitudes of 4000°—5000°, of its largest size near the shores of Puget Sound and in the Redwood-forests of northern California.
3. [Cornus asperifolia] Michx. Dogwood.
Leaves ovate or oblong, gradually or abruptly contracted at apex into a long slender point, gradually narrowed or rounded and cuneate at base, and slightly thickened on the undulate margins, coated with lustrous silvery tomentum when they unfold, and nearly fully grown when the flowers open from the middle of May in Texas to the middle of July at the north, and then dark green and roughened above by short rigid white hairs, and pale, often glaucous or rough-pubescent below, and at maturity thin, scabrous on the upper surface, pubescent or puberulous on the lower surface, 3′—4′ long and 1½′—2′ wide, with a thin midrib, and 4—6 pairs of slender primary veins parallel with their sides; petioles stout, grooved, pubescent, usually about ½′ in length. Flowers cream color, on slender pedicels, in loose broad or narrow often panicled pubescent cymes, on peduncles frequently 1′ in length; calyx oblong, cup-shaped, obscurely toothed, covered with fine silky white hairs; corolla-lobes narrow-oblong, acute, about ⅛′ long, and reflexed after the flowers open; style thickened at apex into a prominent stigma. Fruit ripening from the end of August until the end of October, in loose spreading red-stemmed clusters, subglobose, white, tipped with the remnants of the style, about ¼′ in diameter, with thin dry, bitter flesh, and a full and rounded stone broader than high, somewhat oblique, slightly grooved on the edge, and 1 or 2-seeded; seeds nearly ¼′ long, with a pale brown coat.
A tree, sometimes nearly 50° high, with a short trunk 8′—10′ in diameter, thin erect wand-like branches forming a narrow irregular rather open head, and slender branchlets marked by numerous small pale lenticels, light green and puberulous when they first appear, pale red, lustrous, and puberulous during their first winter, light reddish brown in their second year, and ultimately light gray-brown or gray; usually shrubby. Winter-buds acute, compressed, pubescent, sessile, or stalked, about ⅛′ long, with 2 pairs of opposite scales, the terminal bud nearly twice as large as the compressed lateral buds. Bark of the trunk about ⅛′ thick, and divided by shallow fissures into narrow interrupted ridges broken into small closely appressed dark red-brown scales. Wood close-grained, hard, pale brown, with thick cream-colored sapwood.
Distribution. Southwestern Ontario (Point Pelee and Pelee Island), southward through Ohio, Kentucky, Tennessee and Mississippi to western Florida (Gadsden and Levy Counties) and westward to southeastern South Dakota, southeastern Nebraska, central Kansas, northwestern Oklahoma (near Alva, Woods County) and western Texas (Kerr, Menard and Brown Counties); probably only arborescent on the rich bottom-lands of southern Arkansas and eastern Texas.
4. [Cornus alternifolia] L. Dogwood.
Leaves mostly alternate, clustered at the end of the branches, rarely opposite, oval or ovate, gradually contracted at apex into a long slender point, cuneate or occasionally somewhat rounded at base, obscurely crenulate-toothed on the slightly thickened and incurved margins, coated when they unfold on the lower surface with dense silvery white tomentum, and faintly tinged with red and pilose above, and at maturity thin, bright yellow-green, glabrous or sparsely pubescent on the upper surface, pale or sometimes nearly white and covered with appressed hairs on the lower surface, 3′—5′ long and 2½′—3½′ wide, with a broad orange-colored midrib slightly impressed above, and about 6 pairs of primary veins parallel with their sides; in the autumn turning yellow or yellow and scarlet; petioles slender, pubescent, grooved, 1½′—2′ in length, with an enlarged clasping base. Flowers cream color, opening from the beginning of May to the end of June on slender jointed pedicels ⅛′—¼′ long, in terminal flat puberulous many-flowered cymes 1½′—2½′ wide, mostly on lateral branchlets; calyx cup-shaped, obscurely toothed; corolla-lobes narrow, oblong, rounded at apex, ⅛′ long, reflexed after anthesis; style enlarged into a prominent stigma. Fruit in loose spreading red-stemmed clusters, ripening in October, subglobose, dark blue-black, or rarely yellow (f. ochrocarpa Rehd.), ⅓′ in diameter, tipped with the remnants of the style rising from the bottom of a small depression, with thin and bitter flesh; and an obovoid nutlet, pointed at base, gradually longitudinally many-grooved, thick-walled, and 1 or 2-seeded; seeds lunate, ¼′ long, with a thin membranaceous pale coat.
A flat-topped tree, rarely 25°—30° high, with a short trunk 6′—8′ in diameter, long slender alternate diverging horizontal branches, and numerous short upright slender branchlets pale orange-green or reddish brown when they first appear, mostly light green or sometimes brown tinged with green during their first winter, later turning darker green and marked by pale lunate leaf-scars and small scattered pale lenticels; often a shrub, with numerous stems. Bark of the trunk about ⅛′ thick, dark reddish brown, and smooth or divided by shallow longitudinal fissures into narrow ridges irregularly broken transversely. Wood heavy, hard, close-grained, brown tinged with red, with thick lighter colored sapwood of 20—30 layers of annual growth.
Distribution. Rich woodlands, the margins of the forest, and the borders of streams and swamps, in moist well-drained soil, New Brunswick and Nova Scotia, westward along the valley of the St. Lawrence River to the northern shores of Lake Superior and to Minnesota, and southward through the northern states and along the Appalachian Mountains to North Carolina, up to altitudes of 3500°—4000°; in northern Alabama, southwestern Georgia, and western Florida (River Junction, Gadsden County, T. G. Harbison).
Occasionally cultivated as an ornamental plant in the eastern states.
Section 2. Gamopetalæ. Corolla of united petals (divided in Elliottia in Ericaceæ 0 in some species of Fraxinus in Oleaceæ).
A. Ovary superior (inferior in Vaccinium in Ericaceæ, partly inferior in Symplocaceæ, partly superior in Styraceæ).