B. LEAVES ALTERNATE.
1. Leaves Simple. (2, see p. xxiv).
* Leaves persistent. (** see p. xxii).
a Leaves deeply 3—5-lobed, ⅓′—½′ long, with linear lobes, hoary tomentose below.
Cowania (p. 549).
aa Leaves palmately lobed.
Leaves stellate-pubescent, about 1½′ in diameter, with stipules.
Fremontia (p. 749).
Leaves glabrous, 1°—2° in diameter, without stipules.
Carica (p. 755).
aaa Leaves not lobed or pinnately lobed.
b Branches spinescent.
Leaves clustered at the end of the branches, at least 2′—3′ long.
Bucida (p. 765).
Leaves fascicled on lateral branchlets, obtuse or emarginate, pale and glabrous beneath.
Bumelia angustifolia (p. 816).
Leaves scattered.
Leaves generally obovate, mucronate, not more than ½′—1′ long, glabrous and green or brownish tomentulose beneath.
Condalia (p. 719).
Leaves elliptic-ovate to oblong, obtuse or emarginate, glabrous, 1—2 cm. long.
Ximenia (p. 337).
bb Branches not spinescent.
c Leaves serrate, or lobed (in some species of Quercus). (cc, see p. xxii).
d Juice watery. (dd, see p. xxii).
e Stipules present. (ee, see p. xxii).
f Primary veins extending straight to the teeth.
Leaves and branchlets glabrous or pubescent to tomentose with fascicled hairs.
Leaves fulvous-tomentose beneath, repand-dentate, 3′—5′ long.
Lithocarpus (p. 236).
Leaves glabrous or grayish to whitish tomentose beneath, entire, lobed or dentate.
Quercus sp. 21—34 (p. 268).
Leaves and branchlets coated with simpled silky or woolly hairs at least while young, not more than 2½′ long.
Cercocarpus (p. 550).
ff Primary veins arching and united within the margin.
Leaves 3-nerved from the base.
Ceanothus (p. 726).
Leaves not 3-nerved.
Leaves acute.
Leaves sinuately dentate, with few spiny teeth (rarely entire), glabrous.
Ilex opaca (p. 669).
Leaves serrate.
Leaves tomentose below; branchlets tomentose.
Leaves narrow-lanceolate, glabrous and smooth above.
Vauquelinia (p. 377).
Leaves ovate, cordate, scabrate above.
Trema (p. 327).
Leaves glabrous below.
Heteromeles (p. 392).
Leaves entire, very rarely toothed.
Leaves elliptic, glabrous.
Prunus caroliniana (p. 579).
Leaves oblanceolate, pubescent beneath when young.
Ilex Cassine (p. 670).
Leaves obtuse, sometimes mucronate.
Leaves spinose-serrate, glabrous.
Leaves broad-ovate to suborbicular or elliptic; branchlets dark red-brown, spinescent.
Rhamnus crocea (p. 723).
Leaves ovate to ovate-lanceolate; branchlets yellow or orange-colored, not spinescent.
Prunus ilicifolia (p. 581).
Leaves crenate (often entire), oval to oblong.
Ilex vomitoria (p. 671).
ee Stipules wanting.
Leaves resinous-dotted, aromatic, 1½′—4′ long.
Myrica (p. 163).
Leaves not resinous-dotted, crenately serrate, 4′—6′ long.
Leaves dark green, glabrous below.
Gordonia Lasianthus (p. 751).
Leaves yellowish green, pubescent below, sometimes nearly entire.
Symplocos (p. 831).
dd Juice milky.
Petioles 2½′—4′ long; leaves broad-ovate.
Hippomane (p. 652).
Petioles about ¼′ long; leaves elliptic to oblong-lanceolate.
Gymnanthes (p. 654).
cc Leaves entire (rarely sparingly toothed on vigorous branchlets).
d Stipules present.
e Stipules connate, at least at first.
Stipules persistent, forming a sheath surrounding the branch above the node; leaves obtuse.
Coccolobis (p. 338).
Stipules deciduous, enveloping the unfolded leaf.
Leaves ferrugineous-tomentose beneath.
Magnolia grandiflora (p. 345).
Leaves glabrous beneath, with milky juice.
Ficus (p. 333).
ee Stipules free.
f Juice milky; leaves oval to oblong, 3′—5′ long.
Drypetes (p. 650).
ff Juice watery.
g Leaves obtuse or emarginate at apex.
Leaves with ferrugineous scales beneath, their petioles slender.
Capparis (p. 365).
Leaves without ferrugineous scales.
Leaves soft-pubescent on both sides.
Colubrina cubensis (p. 730).
Leaves glabrous at least at maturity.
Leaves rarely 2′—3′ long, standing on the branch at acute angles.
Chrysobalanus (p. 583).
Leaves rarely more than 1′ long, spreading (sometimes 3-nerved).
Ceanothus spinosos (p. 728).
gg Leaves acute or acutish.
Petioles with 2 glands.
Conocarpus (p. 766).
Petioles without glands.
Leaves and branchlets more or less pubescent, at least while young.
Leaves fascicled except on vigorous branchlets.
Cercocarpus (p. 550).
Leaves not fascicled.
Winter-buds minute, with few pointed scales.
Leaves rounded or nearly rounded at base.
Colubrina sp. 1, 3 (p. 729).
Leaves broad-cuneate at base.
Ilex Cassine (p. 670).
Winter-buds conspicuous, with numerous scales.
Leaves usually lanceolate, entire, covered below with yellow scales.
Castanopsis (p. 234).
Leaves oblong or oblong-obovate, repand-dentate, fibrous tomentose below.
Lithocarpus (p. 236).
Leaves and branchlets glabrous.
Leaf-scar with 1 bundle-trace.
Ilex Krugiana (p. 672).
Leaf-scar with 3 bundle-traces. Cherry Laurels.
Prunus sp. 19—22 (p. 579).
dd Stipules wanting.
e Leaves aromatic when bruised.
Leaves resinous-dotted.
Myrica (p. 163).
Leaves not resinous-dotted.
Leaves obtuse, obovate, glabrous.
Canella (p. 753).
Leaves acute.
Leaves mostly rounded at the narrowed base, ovate to oblong, acute, glabrous.
Anona (p. 354).
Leaves more or less cuneate at base, elliptic to lanceolate, usually acuminate.
Leaves abruptly long-acuminate, glabrous, the margin undulate; branchlets red-brown.
Misanteca (p. 364).
Leaves gradually acuminate or nearly acute.
Leaves strongly reticulate beneath.
Branchlets glabrous, light grayish brown; leaves glabrous, light green beneath.
Ocotea (p. 359).
Branchlets pubescent while young, greenish or yellowish; leaves pale beneath, pubescent while young.
Umbellularia (p. 360).
Leaves not or slightly reticulate, glaucous, glabrous or pubescent beneath.
Persea (p. 356).
ee Leaves not aromatic.
f Leaves acute or acutish.
Leaves obovate, gradually narrowed into short petioles.
Leaves 2′—2½′ long.
Schæfferia (p. 679).
Leaves at least 6′—8′ long.
Enallagma (p. 873).
Leaves elliptic to oblong or ovate.
Leaves rough or pubescent above, pubescent below, subcordate to cuneate at base.
Leaves stellate-pubescent.
Solanum (p. 867).
Leaves scabrous above.
Petiole ⅛′—¼′ long; leaves oval or oblong, 1¼′—4′ long.
Ehretia (p. 862).
Petiole 1′—1½′ long; leaves ovate to oblong-ovate, 3′—7′ long.
Cordia (p. 858).
Leaves smooth above.
Winter-buds scaly.
Leaves covered below with ferrugineous or pale scales, 1′—3′ long.
Lyonia (p. 797).
Leaves glabrous or nearly so below.
Leaves ovate-lanceolate or obovate-lanceolate, 4′—12′ long, usually clustered at end of branchlet, veinlets below obscure.
Rhododendron (p. 792).
Leaves elliptic or oval to oblong or lanceolate.
Leaves light yellowish green below and without distinctly visible veins or veinlets, entire, 3′—4′ long.
Kalmia (p. 794).
Leaves pale below and more or less distinctly reticulate, occasionally serrate or denticulate, 1′—5′ long; bark of branches red.
Arbutus (p. 799).
Winter-buds naked.
Leaves pubescent below when unfolding.
Mature leaves nearly glabrous below.
Leaves oblong-lanceolate to narrow-obovate.
Dipholis (p. 810).
Leaves oval.
Sideroxylum (p. 809).
Mature leaves covered below with brilliant copper-colored pubescence.
Leaves glabrous below.
Chrysophyllum (p. 817).
Leaves marked by minute black dots, ovate to oblong-lanceolate.
Ardisia (p. 806).
Leaves lepidote, oblong-obovate.
Rapanea (p. 807).
ff Leaves obtuse or emarginate at apex.
g Leaves rounded or cordate at base, emarginate, their petioles slender.
Leaves reniform to broad-ovate, cordate; juice watery.
Cercis (p. 603).
Leaves elliptic to oblong, rounded at base; juice milky or viscid.
Leaves emarginate; petioles slender, rufous-tomentulose.
Mimusops (p. 819).
Leaves obtuse at apex; petioles stout, grayish-tomentulose or glabrous.
Rhus integrifolia (p. 664).
gg Leaves cuneate at base.
Petioles slender, ½′ long.
Beureria (p. 861).
Petioles short and stout.
Leaves coriaceous, with thick revolute margins (sometimes opposite).
Jacquinia (p. 804).
Leaves subcoriaceous, slightly revolute.
Leaves reticulate-veined beneath.
Leaves oval to obovate or oblong-oval, more or less pubescent while young.
Vaccinium (p. 802).
Leaves oblong to oblong-obovate, glabrous.
Cyrilla (p. 666).
Leaves obscurely veined beneath, glabrous.
Leaves oblong-lanceolate, narrowed toward the emarginate apex, decurrent nearly to base of petiole.
Cliftonia (p. 667).
Leaves rounded at apex, distinctly petioled.
Maytenus (p. 676).
** Leaves deciduous.
† Leaves conspicuous. (††, see p. xxiv.)
a Leaves entire, sometimes 3 or 4-lobed. (aa, see p. xxiii).
b Stipules present.
Juice milky.
Maclura (p. 331).
Juice watery.
Stipules connate, enveloping the young leaves, their scars encircling the branchlet.
Leaves acute or acuminate, entire; winter-buds pointed, nearly terete.
Magnolia (p. 342).
Leaves truncate, sinuately 4-lobed; winter-buds obtuse, compressed.
Liriodendron (p. 351).
Stipules distinct.
Branches spinescent; leaves glandular, caducous (crenately serrate on vigorous shoots).
Dalea (p. 621).
Branches not spinescent; leaves without glands.
Winter-buds with a single pair of connate scales.
Salix (p. 138).
Winter-buds with several pairs of imbricate scales.
Branchlets without a terminal bud; leaves 3-nerved.
Celtis (p. 318).
Branchlets with a terminal bud, leaves penniveined.
Quercus sp. 17—20 (p. 262).
bb Stipules wanting.
c Branchlets bright green and lustrous for the first 2 or 3 years; leaves sometimes 3-lobed, aromatic.
Sassafras (p. 362).
cc Branchlets brown or gray.
d Leaves acute or acuminate.
Leaves 10′—12′ long, obovate-oblong, acuminate, glabrous, emitting a disagreeable odor.
Asimina (p. 353).
Leaves smaller.
Petioles very slender, 1′—2′ long; leaves elliptic, acuminate.
Cornus alternifolia (p. 789).
Petioles short.
Branchlets with a terminal bud.
Leaf-scars about as long as broad; branchlets without lenticels, light reddish brown.
Elliottia (p. 791).
Leaf-scars crescent-shaped, broader than long, with 3 distinct bundle-traces.
Leaves pubescent on both sides, rugulose above; petioles 1′—2′ long, like the young branchlet densely pubescent.
Leitneria (p. 167).
Leaves glabrous and smooth above, glabrous or pubescent below; petioles and branchlets usually glabrous or nearly so at maturity.
Nyssa (p. 779).
Branchlets without a terminal bud.
Pubescence consisting of simple hairs or wanting.
Leaves 4′—6′ long, pubescent beneath while young; branchlet light brown or gray.
Diospyros virginiana (p. 821).
Leaves 1½′—3′ long, glabrous; branches light yellowish gray.
Schœpfia (p. 336).
Pubescence stellate; leaves obovate or elliptic, 2½′—5′ long, pubescent below.
Styrax (p. 829).
dd Leaves obtuse or acute.
Branchlets not spinescent.
Leaves glabrous at maturity, their petioles slender.
Cotinus (p. 657).
Leaves pubescent below at maturity; their petioles short and thick.
Diospyros texana (p. 823).
Branchlets spinescent; leaves often fascicled on lateral branchlets.
Bumelia (p. 812).
aa Leaves serrate or pinnately lobed.
b Stipules present. (bb, see p. xxvi.)
c Winter-buds naked.
Leaves oblique at base, the upper side rounded or subcordate, obovate, coarsely toothed.
Hamamelis (p. 368).
Leaves equal at base, cuneate, finely serrate or crenate.
Rhamnus sp. 2, 3 (p. 724, 725).
cc Winter-buds with a single pair of connate scales.
Primary veins arching and uniting within the margins; leaves simply serrate or crenate, sometimes entire.
Salix (p. 138).
Primary veins extending to the teeth, leaves doubly serrate, often slightly lobed.
Alnus (p. 220).
ccc Winter-buds with several pairs of imbricate scales.
d Terminal buds wanting; branchlets prolonged by an upper axillary bud.
Juice milky; leaves usually ovate, often lobed.
Morus (p. 328).
Juice watery; leaves not lobed.
Leaves distinctly oblique at base.
Leaves with numerous prominent lateral veins.
Leaves generally broad-ovate, simply serrate, stellate-pubescent at least while young, rarely glabrous.
Tilia (p. 732).
Leaves never broad-ovate, usually doubly serrate, more or less pubescent with simple hairs, at least while young.
Winter-buds ovoid, usually acute, ⅓ to nearly as long as petioles; leaves 1′—7′ long, doubly serrate.
Ulmus (p. 309).
Winter-buds subglobose, minute; leaves 2′—2½′ long, crenate-serrate.
Planera (p. 316).
Leaves 3 or 4-nerved from the base.
Celtis (p. 318).
Leaves slightly or not at all oblique at base.
Leaves 3-nerved from the base, glandular-crenate or glandular-serrate.
Ceanothus (p. 726).
Leaves not or obscurely 3-nerved at base, usually doubly serrate.
Leaves blue-green; petioles ¼′—½′ long; bark smooth, gray-brown.
Carpinus (p. 201).
Leaves yellow-green.
Bark rough, furrowed; petioles ⅛′—¼′ long; leaves not resinous-glandular.
Ostrya (p. 202).
Bark flaky or cherry-tree like; petioles ¼′—1′ long; leaves often resinous-glandular while young.
Betula (p. 205).
dd Terminal buds present.
Primary veins arching and uniting within the margin (extending to the margin in the lobed leaves of Malus).
Winter-buds resinous; leaves crenate, usually truncate at base; petioles slender.
Populus (p. 119).
Winter-buds not resinous.
Leaf-scars with 3 bundle-traces.
Leaves involute in bud, often lobed on vigorous shoots; winter-buds obtuse, short, pubescent.
Malus (p. 379).
Leaves conduplicate (or in some species of Prunus convolute), never lobed; winter-buds acute.
Winter-buds elongated; branches never spinescent.
Amelanchier (p. 393).
Winter-buds not elongated, ovoid; branches sometimes spinescent.
Prunus (p. 555).
Leaf-scars with 1 bundle-trace; leaves simply serrate.
Ilex sp. 5—6 (p. 673).
Primary veins extending to the teeth or to the lobes.
Leaves lobed.
Quercus sp. 1—16, 35—50 (p. 241, 283).
Leaves serrate-toothed.
Winter-buds with numerous scales.
Leaves lustrous beneath, remotely serrate or denticulate; winter-buds elongated, acuminate.
Fagus (p. 228).
Leaves pale beneath, coarsely dentate or serrate; winter-buds acute. Chestnut Oaks.
Quercus sp. 51—54 (p. 303).
Winter-buds with 2 pairs of scales.
Castanea (p. 230).
Leaves doubly or simply serrate, or lobed, with serrate lobes; branches often furnished with spines.
Leaves involute in the bud; branchlets often ending in blunt spines.
Malus (p. 379).
Leaves conduplicate in the bud; branches usually armed with sharp-pointed single or branched axillary spines.
Cratægus (p. 397).
bb Stipules wanting.
c Leaves not lobed.
Leaves subcoriaceous, oblong, sometimes nearly entire, glabrous.
Symplocos (p. 831).
Leaves thin.
Leaves oblong-obovate, acute, pubescent beneath.
Gordonia alatamaha (p. 752).
Leaves oblong or lanceolate, acuminate, glabrous or puberulous while young, turning scarlet in the autumn.
Oxydendrum (p. 796).
Leaves ovate to elliptic, stellate-pubescent or glabrous, turning yellow in the autumn.
Halesia (p. 824).
cc Leaves palmately lobed.
Stipules large, foliaceous, united; branchlets without a terminal bud.
Platanus (p. 371).
Stipules small, free, caducous; branchlets with a terminal bud.
Liquidambar (p. 367).
†† Leaves inconspicuous or wanting; branches spiny or prickly.
Branches or stems succulent, armed with numerous prickles.
Branches and stems columnar, ribbed, continuous; leaves 0.
Cereus (p. 757).
Branches jointed, tuberculate; leaves scale-like.
Opuntia (p. 759).
Branches rigid, spinescent.
Leaves minute, narrow-obovate.
Branchlets bright green.
Kœberlinia (p. 754).
Branchlets red-brown.
Dalea (p. 621).
Leaves scale-like, caducous.
Canotia (p. 677).
2. Leaves compound.
* Leaves 3-foliolate, without stipules.
Leaves persistent; leaflets obovate, entire, sessile.
Hypelate (p. 716).
Leaves deciduous.
Leaflets deltoid to hastate, entire, rounded at apex; branches prickly.
Erythrina (p. 627).
Leaflets ovate to oblong, acuminate, strongly scented and bitter; branches unarmed.
Ptelea (p. 639).
** Leaves twice pinnate; stipules present.
a Leaves unequally twice pinnate, 2°—4° long, deciduous; leaflets serrate, 2′—3′ in length; branches and stem armed with scattered prickles.
Aralia (p. 778).
aa Leaves equally twice pinnate, usually smaller; branches unarmed or armed with stipular or axillary spines (in Parkinsonia often apparently simply pinnate).
b Leaflets crenate; leaves simply or twice-pinnate on the same plant, deciduous, usually armed with simple or branched axillary spines.
Gleditsia (p. 607).
bb Leaflets entire.
Leaflets 2—2½′ long; leaves deciduous; branchlets stout, unarmed.
Gymnocladus (p. 605).
Leaflets smaller; leaves usually persistent; branchlets slender.
Branches armed with prickles or spines.
Leaves with 2 or rarely 4 pinnæ.
Branches armed with axillary spines or spiny rachises.
Pinnæ with 4—8 leaflets; branches with short axillary spines.
Cercidium (p. 613).
Pinnæ with 8—60 leaflets; branches armed with spiny rachises or rigid branchlets terminating in stout spines.
Parkinsonia (p. 611).
Branches armed with stipular prickles; leaves persistent.
Pinnæ with many oblong to linear leaflets.
Prosopis (p. 599).
Pinnæ with 1 pair of orbicular to broad-oblong leaflets.
Pithecolobium unguis-cati (p. 586).
Leaves with 6, or more, rarely 4, pinnæ.
Prickles usually spreading, often recurved.
Acacia (p. 591).
Prickles usually more or less ascending, straight.
Pithecolobium (p. 586).
Branches unarmed.
Branchlets and petioles glabrous; leaves with 2—5 pair of pinnæ, each with 40—80 leaflets.
Lysiloma (p. 589).
Branchlets and petioles pubescent while young; leaves with 5—17 pair of many-foliolate pinnæ, or pinnæ 2—4 and each with 8—16 leaflets.
Leucæna (p. 596).
*** Leaves simply pinnate.
a Leaves equally pinnate.
Stipules wanting.
Leaflets 2—4, generally oblong-obovate.
Exothea (p. 714).
Leaflets 6—12.
Leaflets obtuse, usually oblong-obovate.
Leaflets 8—12, 2′—3′ long, pale below; leaves occasionally opposite.
Simarouba (p. 642).
Leaflets 6—8, 1′—1½′ long, green below.
Xanthoxylum coriaceum (p. 637).
Leaflets 6—8, acuminate.
Swietenia (p. 648).
Stipules present.
Branches armed with infra-stipular spines in pairs; leaflets 10—15, usually oblong-obovate, ½′—¾′ long, persistent.
Olneya (p. 626).
Branches unarmed; leaflets 20—46, ovals ½′—⅔′ long.
Eysenhardtia (p. 620).
aa Leaves unequally pinnate.
b Stipules present.
Leaflets sharply serrate; leaves deciduous; winter-buds resinous.
Sorbus (p. 390).
Leaflets entire or crenately serrate.
Leaves deciduous.
Leaflets 7—11, 3′—4½′ long; branches unarmed.
Leaflets usually alternate, thin and glabrous at maturity.
Cladrastis (p. 618).
Leaflets opposite, coriaceous, pubescent beneath at least along the veins.
Ichthyomethia (p. 628).
Leaflets 9—21, 1—2 cm. long.
Branches usually with stipular prickles, sometimes viscid.
Robinia (p. 622).
Branches unarmed, not viscid; leaflets 13—19, elliptic.
Sophora affinis (p. 617).
Leaves persistent.
Leaflets 7—9, oblong-elliptic, 1′—2½′ long; branches unarmed.
Sophora secundiflora (p. 616).
Leaflets 10—15; branches prickly.
Olneya (p. 626).
bb Stipules wanting.
d Leaves persistent.
Leaflets long-stalked (sometimes nearly sessile in Xanthoxylum flavum).
Leaflets oblong-ovate, cuneate at base.
Leaflets acuminate, glabrous.
Picramnia (p. 643).
Leaflets obtuse, tomentose when unfolding.
Xanthoxylum flavum (p. 636).
Leaflets broad-ovate, usually rounded or subcordate at base.
Metopium (p. 658).
Leaflets sessile or nearly so.
Petiole and rachis winged.
Leaflets crenate, obovate, about ½′ long; branches prickly.
Xanthoxylum Fagara (p. 634).
Leaflets entire.
Leaflets oblong, usually acute, 3′—4′ long.
Sapindus saponaria (p. 712).
Leaflets spathulate, rounded at apex, not more than ¾′ long.
Pistacia (p. 656).
Petiole and rachis not winged.
Leaflets 7—19, acuminate, 2′—5′ long.
Sapindus marginatus (p. 713).
Leaflets 21—41, obtuse, ½′—¾′ long.
Alvaradoa (p. 644).
dd Leaves deciduous.
Leaflets long-stalked, 3—7, entire, acute.
Bursera (p. 645).
Leaflets sessile or nearly so.
Branches prickly; leaflets crenate.
Xanthoxylum clava-Herculis (p. 635).
Branches unarmed.
Juice milky or viscid; leaflets serrate or entire; rachis sometimes winged.
Rhus species 1—3 (p. 660).
Juice watery.
Rachis without wings.
Leaflets entire, acuminate, 7—9.
Sapindus Drummondii (p. 714).
Leaflets serrate or crenate.
Winter-buds large; leaflets 5—23, aromatic.
Winter-buds naked.
Juglans (p. 169).
Winter-buds covered with scales.
Carya (p. 176).
Winter-buds minute, globose, scaly; leaflets 5—7, ovate, not aromatic.
Ungnadia (p. 717).
Rachis winged; leaflets 10—20, entire, rounded at apex, not more than ¼′ long.
Bursera microphylla (p. 647).