Bud-scales valvate, the inner strap-shaped and only occasionally slightly accrescent; fruit more or less broadly winged at the sutures; the thin partitions of the nut containing cavities filled with dark astringent powder (absent in 3 and 5). Shell of the nut thin and brittle; leaflets more or less falcate. Aments of staminate flowers nearly sessile, usually on branches of the previous year; lobes of the seed entire or slightly notched at apex. Leaflets 9—17; nut ovoid-oblong, cylindric; seed sweet.1. [C. pecan] (A, C). Leaflets 7—13; nut oblong, compressed; seed bitter.2. [C. texana] (C). Aments of staminate flowers pedunculate, on branches of the year or of the previous year; lobes of the bitter seed deeply 2-lobed. Leaflets 7—9; nut cylindric or slightly compressed.3. [C. cordiformis] (A, C). Leaflets 7—13; nut compressed, usually conspicuously wrinkled.4. [C. aquatica] (C). Shell of the ellipsoidal cylindric nut thick and hard; lobes of the sweet seed deeply 2-lobed; leaflets 7—9, occasionally 5, rarely slightly falcate; aments of staminate flowers long-pedunculate at the base of branches of the year.5. [C. myristicæformis] (C). Bud-scales imbricated, the inner becoming much enlarged and often highly colored; aments of staminate flowers on peduncles from the base of branches of the year, rarely from the axils of leaves; fruit usually without wings; partitions of the nut thick without cavities filled with astringent powder; seed sweet, its lobes deeply 2-lobed. Branchlets usually stout (slender in 7); involucre ¼′—½′ in thickness, opening freely to the base. Bark on old trunks separating into long, broad, loosely attached plates; nuts pale. Branchlets light red-brown; shell of the nut thin. Leaflets 5 or rarely 7, obovate to ovate, acute or acuminate; nut much compressed, often long-pointed at apex; branchlets glabrous or pubescent.6. [C. ovata] (A, C). Leaflets 5, lanceolate, acuminate; nut little compressed, acute at apex; branchlets slender, glabrous.7. [C. carolinæ-septentrionalis] (C). Branchlets pale orange color, pubescent; leaflets usually 7—9; shell of the nut thick.8. [C. laciniosa] (A, C). Bark not scaly, on old trunks dark, deeply ridged; leaflets 7—9, often subcoriaceous, pubescent below; nut reddish brown, often long-pointed, thick shelled; branchlets pubescent.9. [C. alba] (A, C). Branchlets slender; leaves 5—7-foliolate; involucre of the fruit tardily dehiscent to the middle, indehiscent or opening freely to the base; shell of the nut thick, bark close, (sometimes scaly in 13). Branchlets and leaves not covered when they first appear with rusty brown pubescence. Involucre of the fruit 3—5.5 mm. in thickness, opening freely to the base, leaves usually 7-foliolate; winter-buds pubescent. Leaflets hoary tomentose below in early spring, slightly pubescent at maturity; petioles and rachis glabrous; fruit broad-obovoid; branchlets glabrous.10. [C. leiodermis] (C). Leaflets covered in early spring with silvery scales, pale and pubescent below during the season; petioles and rachis more or less thickly covered with fascicled hairs; fruit ellipsoidal to obovoid or globose; branchlets glabrous or slightly pubescent.11. [C. pallida] (A, C). Involucre of the fruit 1—3 mm. in thickness; winter-buds glabrous or puberulous. Leaves 5, rarely 7-foliolate, glabrous or rarely slightly pubescent; fruit obovoid, often narrowed below into a stipitate base, the involucre indehiscent or tardily dehiscent.12. [C. glabra] (A, C). Leaves generally 7-foliolate, glabrous or rarely pubescent; fruit ellipsoidal, subglobose or obovoid, the involucre opening freely to the base; bark often more or less scaly.13. [C. ovalis] (A, C). Branchlets and leaves densely covered when they first appear with rusty brown pubescence; leaflets usually 5—7; winter-buds rusty pubescent. Fruit obovoid; the involucre 2—3 mm. in thickness; peduncles of the aments of staminate flowers often from the axils of leaves; branchlets soon becoming glabrous.14. [C. floridana] (C). Fruit subglobose to broadly obovoid, ellipsoidal or pyriform, the involucre on the different varieties 2—13 mm. in thickness; branchlets pubescent through their first season.15. [C. Buckleyi] (A, C).
1. [Carya pecan] Asch. & Gr. Pecan.
Leaves 12′—20′ long, with slender glabrous or pubescent petioles, and 9—17 lanceolate to oblong-lanceolate more or less falcate long-pointed coarsely often doubly serrate leaflets rounded or cuneate at the unequal base; sessile, except the terminal leaflet, or short-stalked, dark yellow-green and glabrous or pilose above, and pale and glabrous or pubescent below, 4′—8′ long, 1′—3′ wide, with a narrow yellow midrib and conspicuous veins. Flowers: staminate in slender puberulous clustered aments 3′—5′ long, from buds formed in the axils of leaves of the previous year or occasionally on shoots of the year, sessile or short-stalked, light yellow-green and hirsute on the outer surface, with broadly ovate acute lobes rather shorter than the oblong or obovate bract; stamens 5′ or 6′; anthers yellow, slightly villose; pistillate in few or many flowered spikes, oblong, narrowed at the ends, slightly 4-angled and coated with yellow scurfy pubescence. Fruit in clusters of 3—11, pointed at apex, rounded at the narrowed base, 4-winged and angled, 1′—2½′ long, ½′—1′ broad, dark brown and more or less thickly covered with yellow scales, with a thin, brittle husk splitting at maturity nearly to the base and often persistent on the branch during the winter after the discharge of the nut; nut ovoid to ellipsoidal, nearly cylindric or slightly 4-angled toward the pointed apex, rounded and usually apiculate at base, bright reddish brown, with irregular black markings with a thin shell and papery partitions; seed sweet, red-brown, its nearly flat lobes grooved from near the base to the apex by 2 deep longitudinal grooves.
A tree, 100°—180° high, with a tall massive trunk occasionally 6° or 7° in diameter above its enlarged and buttressed base, stout slightly spreading branches forming in the forest a narrow symmetrical and inversely pyramidal head, or with abundant room a broad round-topped crown, and branchlets at first slightly tinged with red and coated with loose pale tomentum, becoming glabrous or puberulous in their first winter, and marked by numerous oblong orange-colored lenticels and by large oblong concave leaf-scars with a broad thin membranaceous border surrounding the lower axillary bud. Winter-buds acute, compressed, covered with clusters of bright yellow articulate hairs and pale tomentum; terminal ½′ long; axillary ovoid, often stalked, especially the large upper bud. Bark 1′—1½′ thick, light brown tinged with red, and deeply and irregularly divided into narrow forked ridges broken on the surface into thick appressed scales. Wood heavy, hard, not strong, brittle, coarse-grained, light brown tinged with red, with thin light brown sapwood; less valuable than that of most Hickories, and used chiefly for fuel, and occasionally in the manufacture of wagons and agricultural implements. The nuts, which vary in size and shape and in the thickness of their shells and in the quality of the kernels, are an important article of commerce.
Distribution. Low rich ground in the neighborhood of streams; in the valley of the Mississippi River, Iowa (Clinton and Muscatine Counties), southern Illinois, southwestern Indiana (Sullivan and Spencer Counties), western Kentucky and Tennessee, western Mississippi and Louisiana, extreme western and southwestern Missouri (Jackson County southward, common only on the Marias de Cygne River), eastern Kansas to Kickapoo Island in the Missouri River near Fort Leavenworth, Oklahoma to the valley of the Salt Fork of the Arkansas River (near Alva, Woods County) and to creek valleys near Cache, Comanche County (G. W. Stevens), through Arkansas; and in Texas to the valley of the Devil’s River and to that of Warder’s Creek, Hardiman County; reappearing on the mountains of Mexico; most abundant and of its largest size in southern Arkansas and eastern Texas.
Largely cultivated in the Southern States, in many selected varieties, for its valuable nuts.
2. [Carya texana] Schn. Bitter Pecan.
Leaves 10′—12′ long, with slender petioles, and 7—13 lanceolate acuminate finely serrate leaflets, hoary-tomentose when they unfold, and more or less villose in the autumn, thin and firm, dark yellow-green and nearly glabrous above, pale yellow-green and puberulous below, 3′—5′ long, about 1½′ wide, the terminal leaflet gradually narrowed to the acute base and short-stalked, the lateral often falcate, unsymmetrical at the base, subsessile or short-stalked. Flowers: staminate in villose aments 2′—3′ long, light yellow-green and villose on the outer surface, with oblong-ovate rounded lobes; pistillate in few fruited spikes, oblong, slightly 4-angled, villose. Fruit oblong or oblong-obovoid, apiculate at apex, slightly 4-winged at base, dark brown, more or less covered with yellow scales, 1½′—2′ long, with a thin husk; nut oblong-ovoid or oblong-obovoid, compressed, acute at the ends, short-pointed at apex, apiculate at base, obscurely 4-angled, bright red-brown, rough and pitted, with a thin brittle shell, thin papery walls, and a low basal ventral partition; seed very bitter, bright red-brown, flattened, its lobes rounded and slightly divided at apex, longitudinally grooved and deeply penetrated on the outer face by the prominent reticulated folds of the inner surface of the shell of the nut.