Chapter VI: Section 2: Gamopetalæ. Corolla of united petals (divided in Elliottia (1)

in Ericaceæ, 0 in some species of Fraxinus in Oleaceæ_).

A. Ovary superior (_inferior in Vaccinium in Ericaceæ, partly inferior in Symplocaceæ and Styracaceæ_).

LIII. Ericaceæ (p. 790). Flowers perfect; calyx and corolla 5-lobed
(_in Elliottia corolla of 4 petals_); (_ovary inferior in
Vaccinium_); fruit capsular, drupaceous or baccate; leaves
simple, alternate, without stipules, persistent (_deciduous in
Elliottia and Oxydendrum_).
LIV. Theophrastaceæ (p. 804). Flowers perfect, with staminodia; sepals
and petals 5; stamens 5; fruit a berry; leaves simple,
opposite or alternate, entire, without stipules.
LV. Myrsinaceæ (p. 805). Flowers perfect; calyx and corolla 5-lobed;
stamens 5; fruit a drupe; leaves simple, alternate, entire,
without stipules, persistent.
LVI. Sapotaceæ (p. 808). Flowers perfect; calyx 5-lobed; corolla
5-lobed (_6-lobed in Mimusops_), often with as many or twice
as many internal appendages borne on its throat; fruit a
berry; leaves simple, alternate, without stipules, persistent
(_deciduous in some species of Bumelia_).
LVII. Ebenaceæ (p. 820). Flowers perfect, diœcious, or polygamous;
calyx and corolla 4-lobed; fruit a 1 or several-seeded berry;
leaves simple, alternate, entire, without stipules, deciduous.
LVIII. Styraceæ (p. 824). Flowers perfect; calyx 4 or 5-toothed;
corolla 4 or 5-lobed or divided nearly to the base, or rarely
6 or 7-lobed; ovary superior or partly superior; fruit a
drupe; leaves simple, alternate, without stipules, deciduous;
pubescence mostly scurfy or stellate.
LIX. Symplocaceæ (p. 830). Flowers perfect; calyx and corolla 5-lobed;
ovary inferior or partly inferior; fruit a drupe; leaves
simple, alternate, without stipules, deciduous; pubescence
simple.
LX. Oleaceæ (p. 832). Flowers perfect or polygamo-diœcious; calyx
4-lobed (_0 in some species of Fraxinus_); corolla 2—6-parted
(_0 in some species of Fraxinus_); fruit a winged samara
(Fraxinus) or a fleshy drupe (Forestiera, Chionanthus and
Osmanthus); leaves pinnate (Fraxinus) or simple, opposite,
without stipules, deciduous (_persistent in Osmanthus_).
LXI. Borraginaceæ (p. 858). Flowers perfect or polygamous; calyx and
corolla 5-lobed; fruit a drupe; leaves simple, alternate,
scabrous-pubescent, without stipules, persistent or tardily
deciduous.
LXII. Verbenaceæ (p. 864). Flowers perfect; calyx 5-lobed; corolla 4
or 5-lobed; fruit a drupe or a 1-seeded capsule; leaves
simple, opposite, without stipules, persistent.
LXIII. Solanaceæ (p. 867). Flowers perfect; calyx campanulate, usually
5-lobed; corolla usually 5-lobed; fruit baccate, surrounded at
base by the enlarged calyx; leaves alternate, rarely opposite,
without stipules.
LXIV. Bignoniaceæ (p. 868). Flowers perfect; calyx bilabiate; corolla
bilabiate, 5-lobed; fruit a woody capsule (Catalpa and
Chilopsis) or a berry (Enallagma); leaves simple, opposite
(_sometimes alternate in Chilopsis_), without stipules,
deciduous (_persistent in Enallagma_).

B. Ovary inferior (_partly superior in Sambucus in Caprifoliaceæ_).

LXV. Rubiaceæ (p. 875). Flowers perfect; calyx and corolla 4 or
5-lobed; fruit a capsule (Exostema and Pinckneya), a drupe
(Guettarda), or nut-like (Cephalanthus); leaves simple
opposite, or in verticils of 3 (Cephalanthus), with stipules,
persistent (_deciduous in Pinckneya and Cephalanthus_).
LXVI. Caprifoliaceæ (p. 882). Flowers perfect; calyx and corolla
5-lobed; fruit a drupe; leaves unequally pinnate (Sambucus) or
simple (Viburnum), opposite, without stipules, deciduous in
North American species.

ANALYTICAL KEY
TO THE GENERA OF PLANTS INCLUDED IN THIS BOOK, BASED CHIEFLY ON THE
CHARACTER OF THE LEAVES

I. Leaves parallel-veined, alternate, persistent, clustered at the end
of the stem or branches. Monocotyledons.
Stem simple; leaves stalked.
Leaves fan-shaped.
Leaf stalks unarmed.
Rachis short; leaves usually silvery white below.
Leaves 2°—4° in diameter (_green below in No. 2_), their
segments undivided at apex.
Thrinax (p. 96).
Leaves 18′—24′ in diameter, their segments divided at apex.
Coccothrinax (p. 100).
Rachis elongated; leaves green below, their segments divided at
apex.
Sabal (p. 101).
Leaf stalks armed with marginal teeth or spines.
Leaf stalks furnished irregularly with broad thin large and
small, straight or hooked spines confluent into a thin
bright orange-colored cartilaginous margin; leaves longer
than wide, divided nearly to the middle into segments
parted at apex and separating on the margins into thin
fibres.
Washingtonia (p. 104).
Leaf stalks furnished with stout or slender flattened teeth;
leaves suborbicular, divided to the middle or nearly to
the base into segments parted at apex; segments of the
blade not separating on the margin into thin fibres.
Acœlorraphe (p. 105).
Leaves pinnate.
Leaves 10°—12° in length, their pinnæ 2½°—3° long and often 1½°
wide, deep green.
Roystonea (p. 107).
Leaves 5°—6° long, their pinnæ 18′ long and 1′ wide, dark
yellow-green above, pale and glaucous below.
Pseudophœnix (p. 109).
Stem simple or branched; leaves sessile, lanceolate, long- and usually
sharp-pointed at apex.
Yucca (p. 110).

II. Leaves 1-nerved, needle-shaped, linear or scale-like, persistent
(deciduous in Larix and Taxodium). Gymnospermæ.

1. Leaves Persistent.

_a_ Leaves fascicled, needle-shaped, in 1—5-leafed clusters enclosed
at base in a membranaceous sheath.
Pinus (p. 2).
_aa_ Leaves scattered, usually linear.
_b_ Leaves linear, often obtuse or emarginate.
Base of the leaves persistent on the branches.
Leaves sessile, 4-sided, or flattened and stomatiferous above.
Picea (p. 34).
Leaves stalked, flattened and stomatiferous below, or angular,
often appearing 2-ranked.
Tsuga (p. 42).
Base of the leaves not persistent on the branches; leaves often
appearing 2-ranked.
Leaves stalked, flattened, stomatiferous below; winter-buds
pointed, not resinous.
Pseudotsuga (p. 47).
Leaves sessile, flattened and often grooved on the upper side,
or quadrangular, rarely stomatiferous above, on upper
fertile branches often crowded; winter-buds obtuse,
resinous (_except in No. 9_).
Abies (p. 50).
_bb_ Leaves linear-lanceolate, rigid, acuminate, spirally disposed,
appearing 2-ranked by a twist in the petiole.
Leaves abruptly contracted at base, long-pointed, with pale bands
of stomata on the lower surface on each side of the
midveins; fruit drupe-like.
Torreya (p. 91).
Leaves gradually narrowed at base, short-pointed, paler, and
without distinct bands of stomata on the lower surface;
fruit berry-like.
Taxus (p. 93).
_bbb_ Leaves ovate-lanceolate and scale-like, spreading in 2 ranks
or linear on the same tree, acute, compressed, keeled on the
back and closely appressed or spreading at apex.
Sequoia (p. 61).
_aaa_ Leaves opposite or whorled, usually scale-like.

Internodes distinctly longer than broad; branchlets flattened, of
nearly equal color on both sides; leaves eglandular.
Libocedrus (p. 65).
Internodes about as long as broad, often pale below, usually
glandular.
Branchlets flattened.
Branchlets in one plane, much flattened, 1/12′—⅙′ broad.
Thuya (p. 67).
Branchlets slightly flattened, 1/24′—1/16′ broad.
Chamæcyparis (p. 75).
Branchlets terete or 4-angled.
Branchlets more or less in one plane; fruit a cone.
Cupressus (p. 69).
Branchlets not in one plane; fruit a berry (_leaves
needle-shaped, in whorls of 3 in No. 1_).
Juniperus (p. 78).

2. Leaves Deciduous.

Leaves in many-leafed clusters on short lateral spurs.
Larix (p. 31).
Leaves spreading in 2 ranks.
Taxodium (p. 63).

III. Leaves netted-veined, rarely scale-like or wanting. Dicotyledons.

A. LEAVES OPPOSITE. (B, see p. xix).

1. Leaves Simple. (2, see p. xviii).

Leaves persistent.

_a_ Leaves with stipules.
_b_ Leaves entire or occasionally slightly crenate or serrate.
_c_ Leaves emarginate at apex, very short-stalked, 1½′—2′ long.
Leaves obovate, gradually narrowed into the petiole.
Gyminda (p. 678).
Leaves oval to oblong, rounded or broad-cuneate (_rarely
alternate_).
Branchlets densely velutinous.
Krugiodendron (p. 721).
Branchlets slightly puberulous at first, soon glabrous.
Reynosia (p. 720).
_cc_ Leaves not emarginate at apex.
Leaves obtuse, rarely acutish or abruptly short-pointed.
Leaves elliptic, 3½′—5′ long.
Rhizophora (p. 763).
Leaves obovate, usually rounded at apex, ¾′—2′ long.
Byrsonima (p. 632).
Leaves acute to acuminate.
Leaves oblong-ovate to lanceolate; branchlets glabrous.
Exostema (p. 877).
Leaves broad-elliptic to oblong-elliptic; branchlets villose.
Guettarda (p. 879).
_bb_ Leaves serrate (_often pinnate_).
Lyonothamnus (p. 378).
_aa_ Leaves without stipules.
Petioles biglandular; leaves obtuse or emarginate, 1½′—2½′ long.
Laguncularia (p. 767).
Petioles without glands.
Leaves furnished below with small dark glands, slightly aromatic;
petioles short.
Leaves oblong to oblong-ovate and acuminate or elliptic and
bluntly short-pointed.
Calyptranthes (p. 769).
Leaves ovate, obovate or elliptic.
Eugenia (p. 770).
Leaves without glands.
Leaves green and glabrous below.
Leaves obtuse or emarginate at apex (_rarely alternate_),
1′—1½′ long.
Torrubia (p. 341).
Leaves acute, acuminate, or sometimes rounded or emarginate,
3′—5′ long.
Leaves distinctly veined.
Citharexylon (p. 864).
Leaves obscurely veined.
Osmanthus (p. 856).
Leaves hoary tomentulose or scurfy below.
Leaves strongly 3-nerved, acuminate, densely scurfy below.
Tetrazygia (p. 776).
Leaves penniveined, rounded or acute at apex, hoary
tomentulose below.
Avicennia (p. 865).

** Leaves deciduous.
_a_ Leaves without lobes.
_b_ Leaves serrate.
Winter-buds with several opposite outer scales.
Leaves puberulous below, closely and finely serrate; axillary
buds solitary.
Evonymus (p. 675).
Leaves glabrous below, remotely crenate-serrulate; axillary buds
several, superposed.
Forestiera (p. 853).
Winter-buds enclosed in 2 large opposite scales.
Viburnum (p. 886).
_bb_ Leaves entire.
_c_ Leaves without stipules.
Leaves suborbicular or elliptic to oblong.
Leaves rounded or acutish at apex, 1′—2′ long, occasionally
3-foliolate, glabrous; branchlets quadrangular.
Fraxinus anomala (p. 837).
Leaves acuminate or acute at apex, 3′—4′ long.
Leaf-scars connected by a transverse line, with 3
bundle-traces; branchlets slender,
appressed-pubescent.
Cornus (p. 785).
Leaf-scars not connected, with 1 bundle-trace; branchlets
stout, villose, puberulous or glabrous.
Chionanthus (p. 855).
Leaves broad-ovate, cordate, acuminate, 5′—12′ long, on long
petioles.
Catalpa (p. 870).
Leaves linear to linear-lanceolate, short-stalked or sessile
(_sometimes alternate_).
Chilopsis (p. 869).
_cc_ Leaves with persistent stipules, entire.
Leaves oval or ovate; winter-buds resinous, the terminal up to
½′ in length.
Pinckneya (p. 876).
Leaves ovate to lanceolate; winter-buds minute.
Cephalanthus (p. 878).
_aa_ Leaves palmately lobed.
Acer (p. 681).

2. Leaves Compound.

_a_ Leaves persistent, with stipules.
Leaves equally pinnate; leaflets entire.
Guaiacum (p. 630).
Leaves unequally pinnately parted into 3—8 linear-lanceolate
segments (_sometimes entire_).
Lyonothamnus (p. 378).
Leaves trifoliate.
Leaflets stalked.
Amyris (p. 640).
Leaflets sessile.
Helietta (p. 637).
_aa_ Leaves deciduous.
Leaves unequally pinnate or trifoliate.
Leaflets crenate-serrate or entire, the veins arching within the
margins; stipules wanting; winter-buds with several opposite
scales.
Fraxinus (p. 833).
Leaflets sharply or incisely serrate, the primary veins extending
to the teeth.
Leaflets 3—7, incisely serrate; stipules present; winter-buds
with 1 pair of obtuse outer scales.
Acer Negundo (p. 699).
Leaflets 5—9, sharply serrate; stipules present; winter-buds
with many opposite acute scales; pith thick.
Sambucus (p. 882).
Leaves digitate, with 5—7, sharply serrate leaflets; terminal buds
large.
Æsculus (p. 702).

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).

TREES OF NORTH AMERICA
(Exclusive of Mexico)

Class 1. GYMNOSPERMÆ.

Ovules and seeds borne on the face of a scale, not inclosed in an ovary; resinous trees, with stems increasing in diameter by the annual addition of a layer of wood inside the bark.

I. PINACEÆ.

Trees, with narrow or scale-like generally persistent clustered or alternate leaves and usually scaly buds. Flowers appearing in early spring, mostly surrounded at the base by an involucre of the more or less enlarged scales of the buds, unisexual, monœcious (_diœcious in Juniperus_), the male consisting of numerous 2-celled anthers, the female of scales bearing on their inner face 2 or several ovules, and becoming at maturity a woody cone or rarely a berry. Seeds with or without wings; seed-coat of 2 layers; embryo axile in copious albumen; cotyledons 2 or several. Of the twenty-nine genera scattered over the surface of the globe, but most abundant in northern temperate regions, thirteen occur in North America.

CONSPECTUS OF THE NORTH AMERICAN GENERA.

Scales of the female flowers numerous; spirally arranged in the axils
of persistent bracts; ovules 2, inverted; seeds borne directly
on the scales, attached at the base in shallow depressions on
the inner side of the scales, falling from them at maturity and
usually carrying away a scarious terminal wing; leaves fascicled
or scattered (_deciduous in Larix_). Abietineæ.
Fruit maturing in two or rarely in three seasons; leaves fascicled,
needle-shaped in axillary 1—5-leaved clusters, inclosed at the
base in a membranaceous sheath; cone-scales thick and woody,
much longer than their bracts.
1. Pinus.
Fruit maturing in one season.
Leaves in many-leaved clusters on short spur-like branchlets,
deciduous; cone-scales thin, usually shorter than their
bracts.
2. Larix.
Leaves scattered, linear.
Cones pendulous, the scales persistent on the axis.
Branchlets roughened by the persistent leaf-bases; leaves
deciduous in drying; bracts shorter than the
cone-scales.
Leaves sessile, 4-sided, or flattened and stomatiferous
above.
3. Picea.
Leaves stalked, flattened and stomatiferous below, or
angular.
4. Tsuga.
Branchlets not roughened by leaf-bases; leaves stalked,
flattened; not deciduous in drying; bracts of the cone
2-lobed, aristate, longer than the scales.
5. Pseudotsuga.
Cones erect, their scales deciduous from the axis, longer or
shorter than the bracts; leaves sessile, flat or 4-sided.
6. Abies.
Scales of the female flowers without bracts; ovules and seeds borne on
the face of minute scales adnate to the base of the
flower-scales, enlarging and forming the scales of the cone.
Seeds with a narrow marginal wing (_wingless in Juniperas_).
Scales of the female flowers numerous, spirally arranged, forming a
woody cone; ovules erect, 2 or many under each scale; leaves
linear, alternate, often of 2 forms (_deciduous in Taxodium_).
Taxodiæ.
Ovules and seeds numerous under each scale.
7. Sequoia.
Ovules and seeds 2 under each scale; leaves mostly spreading in 2
ranks.
8. Taxodium.
Scales of the female flower few, decussate, forming a small cone, or
rarely a berry; ovules 2 or many under each scale; leaves
decussate or in 3 ranks, often of 2 forms, usually scale-like,
mostly adnate to the branch, the earliest free and subulate.
Cupressineæ.
Fruit a cone; leaves scale-like.
Cones oblong, their scales oblong, imbricated or valvate; seeds
2 under each scale, maturing the first year.
Scales of the cone 6, the middle ones only fertile; seeds
unequally 2-winged.
9. Libocedrus.
Scales of the cone 8—12; seeds equally 2-winged.
10. Thuja.
Cones subglobose, the scales peltate, maturing in one or two
years; seeds few or many under each scale.
Fruit maturing in two seasons; seeds many under each scale;
branchlets terete or 4-winged.
11. Cupressus.
Fruit maturing in one season; seeds 2 under each scale;
branchlets flattened.
12. Chamæcyparis.
Fruit a berry formed by the coalition of the scales of the flower;
ovules in pairs or solitary; flowers diœcious; leaves
decussate or in 3’s, subulate or scale-like, often of 2
forms.
13. Juniperus.

1. PINUS Duham. Pine.

Trees or rarely shrubs, with deeply furrowed and sometimes laminate or with thin and scaly bark, hard or often soft heartwood often conspicuously marked by dark bands of summer cells impregnated with resin, pale nearly white sapwood, and large branch-buds formed during summer and composed of minute buds in the axils of bud-scales, becoming the bracts of the spring shoot. Leaves needle-shaped, clustered, the clusters borne on deciduous spurs in the axils of scale-like primary leaves, inclosed in the bud by numerous scales lengthening and forming a more or less persistent sheath at the base of each cluster. Male flowers clustered at the base of leafy growing shoots of the year, each flower surrounded at the base by an involucre of 3—6 scale-like bracts, composed of numerous sessile anthers, imbricated in many ranks and surmounted by crest-like nearly orbicular connectives; the female subterminal or lateral, their scales in the axils of non-accrescent bracts. Fruit a woody cone maturing at the end of the second or rarely of the third season, composed of the hardened and woody scales of the flower more or less thickened on the exposed surface (the _apophysis_), with the ends of the growth of the previous year appearing as terminal or dorsal brown protuberances or scars (the _umbo_). Seeds usually obovoid, shorter or longer than their wings or rarely wingless; outer seed-coat crustaceous or thick, hard, and bony, the inner membranaceous; cotyledons 3—18, usually much shorter than the inferior radicle.

Pinus is widely distributed through the northern hemisphere from the Arctic Circle to the West Indies, the mountains of Central America, the Canary Islands, northern Africa, the Philippine Islands, and Sumatra. About sixty-six species are recognized. Of exotic species the so-called Scotch Pine, _Pinus sylvestris_ L., of Europe and Asia, the Swiss Stone Pine, _Pinus cembra_ L., and the Austrian Pine and other forms of _Pinus nigra_ Arnold, from central and southern Europe, are often planted in the northeastern states, and _Pinus Pinaster_ Ait., of the coast region of western France and the Mediterranean Basin is successfully cultivated in central and southern California. _Pinus_ is the classical name of the Pine-tree.

The North American species can be conveniently grouped in two sections, Soft Pines and Pitch Pines.

SOFT PINES.

Wood soft, close-grained, light-colored, the sapwood thin and nearly white; sheaths of the leaf-clusters deciduous; leaves with one fibro-vascular bundle.

Leaves in 5-leaved clusters.
Cones long-stalked, elongated, cylindric bright green at maturity,
becoming light yellow brown, their scales thin, with terminal
unarmed umbos; seeds shorter than their wings. White Pines.
Leaves without conspicuous white lines on the back.
Leaves slender, flexible; cones 4′—8′ long.
1. P. Strobus (A).
Leaves stout, more rigid; cones 5′—11′ long.
2. P. monticola (B, G).
Leaves with conspicuous white lines on the back; cones 12′—18′
long.
3. P. Lambertiana (G).
Cones short-stalked, green or purple at maturity, their scales
thick.
Cones cylindric or subglobose, their scales with terminal umbos;
leaves 2′ long or less. Stone Pines.
Cones 3′—10′ long, their scales opening at maturity; seeds with
wings.
4. P. flexilis (F, H).
Cones ½′—3′ long, their scales remaining closed at maturity;
seeds wingless.
5. P. albicaulis (B, F, G).
Cones ovoid-oblong, their scales with dorsal umbos armed with
slender prickles; seeds shorter than their wings; leaves in
crowded clusters, incurved, less than 2′ long. Foxtail
Pines.
Cones armed with minute incurved prickles.
6. P. Balfouriana (G).
Cones armed with long slender prickles.
7. P. aristata (F, G).
Leaves in 1—4-leaved clusters; cones globose, green at maturity,
becoming light brown, their scales few, concave, much thickened,
only the middle scales seed-bearing; seeds large and edible,
their wings rudimentary; leaves 2′ or less, often incurved. Nut
Pines.
8. P. cembroides (C, F, G, H).

1. Pinus Strobus L. White Pine.

Leaves soft bluish green, whitened on the ventral side by 3—5 bands of stomata, 3′—5′ long, mostly turning yellow and falling in September in their second season, or persistent until the following June. Flowers: male yellow; female bright pink, with purple scale margins. Fruit fully grown in July of the second season, 4′—8′ long, opening and discharging its seeds in September; seeds narrowed at the ends, ¼′ long, red-brown mottled with black, about one fourth as long as their wings.

A tree, while young with slender horizontal or slightly ascending branches in regular whorls usually of 5 branches; at maturity often 100°, occasionally 220° high, with a tall straight stem 3°—4° or rarely 6° in diameter, when crowded in the forest with short branches forming a narrow head, or rising above its forest companions with long lateral branches sweeping upward in graceful curves, the upper branches ascending and forming a broad open irregular head, and slender branchlets coated at first with rusty tomentum, soon glabrous, and orange-brown in their first winter. Bark on young stems and branches thin, smooth, green tinged with red, lustrous during the summer, becoming 1′—2′ thick on old trunks and deeply divided by shallow fissures into broad connected ridges covered with small closely appressed purplish scales. Wood light, not strong, straight-grained, easily worked, light brown often slightly tinged with red; largely manufactured into lumber, shingles, and laths, used in construction, for cabinet-making, the interior finish of buildings, wooden ware, matches, and the masts of vessels.

Distribution. Newfoundland to Manitoba, southward through the northern states to Pennsylvania, northern and eastern (Belmont County) Ohio, northern Indiana, valley of the Rocky River near Oregon, Ogle County, Illinois, and central and southeastern Iowa, and along the Appalachian Mountains to eastern Kentucky and Tennessee and northern Georgia; forming nearly pure forests on sandy drift soils, or more often in small groves scattered in forests of deciduous-leaved trees on fertile well-drained soil, also on the banks of streams, or on river flats, or rarely in swamps.

Largely planted as an ornament of parks and gardens in the eastern states, and in many European countries, where it grows with vigor and rapidity; occasionally used in forest planting in the United States.

2. Pinus monticola D. Don. White Pine.

Leaves blue-green, glaucous, whitened by 2—6 rows of ventral and often by dorsal stomata, mostly persistent 3 or 4 years. Flowers: male yellow; female pale purple. Fruit 5′—11′ long, shedding its seeds late in the summer or in early autumn; seeds narrowed at the ends, ⅓′ long, pale red-brown mottled with black, about one third as long as their wings.

A tree, often 100° or occasionally 150° high, with a trunk frequently 4°—5° or rarely 7°—8° in diameter, slender spreading slightly pendulous branches clothing young stems to the ground and in old age forming a narrow open often unsymmetrical pyramidal head, and stout tough branchlets clothed at first with rusty pubescence, dark orange-brown and puberulous in their first and dark red-purple and glabrous in their second season. Bark of young stems and branches thin, smooth, light gray, becoming on old trees ¾′—1½′ thick and divided into small nearly square plates by deep longitudinal and cross fissures, and covered by small closely appressed purple scales. Wood light, soft, not strong, close, straight-grained, light brown or red; sometimes manufactured into lumber, used in construction and the interior finish of buildings.

Distribution. Scattered through mountain forests from the basin of the Columbia River in British Columbia to Vancouver Island; on the mountains of northern Washington to the western slopes of the Rocky Mountains of northern Montana; on the coast ranges of Washington and Oregon; and on the Cascade and Sierra Nevada ranges southward to the Kern River valley, California; most abundant and of its greatest value in northern Idaho on the bottom-lands of streams tributary to Lake Pend Oreille; reaching the sea-level on the southern shores of the Straits of Fuca and elevations of 10,000° on the California Sierras.

Often planted as an ornamental tree in Europe, and occasionally in the eastern United States where it grows more vigorously than any other Pine-tree of western America.

3. Pinus Lambertiana Dougl. Sugar Pine.

Leaves stout, rigid, 3½′—4′ long, marked on the two faces by 2—6 rows of stomata; deciduous during their second and third years. Flowers: male light yellow; female pale green. Fruit fully grown in August and opening in October, 11′—18′ or rarely 21′ long; seeds ½′—⅝′ long, dark chestnut-brown or nearly black, and half the length of their firm dark brown obtuse wings broadest below the middle and ½′ wide.

A tree, in early life with remote regular whorls of slender branches often clothing the stem to the ground and forming an open narrow pyramid; at maturity 200°-220° high, with a trunk 6°—8° or occasionally 12° in diameter, a flat-topped crown frequently 60° or 70° across of comparatively slender branches sweeping outward and downward in graceful curves, and stout branchlets coated at first with pale or rufous pubescence, dark orange-brown during their first winter, becoming dark purple-brown. Bark on young stems and branches thin, smooth, dark green, becoming on old trunks 2′—3′ thick and deeply and irregularly divided into long thick plate-like ridges covered with large loose rich purple-brown or cinnamon-red scales. Wood light, soft, straight-grained, light red-brown; largely manufactured into lumber and used for the interior finish of buildings, woodwork, and shingles. A sweet sugar-like substance exudes from wounds made in the heartwood.

Distribution. Mountain slopes and the sides of ravines and cañons; western Oregon from the valley of the north branch of the Santiam River southward on the Cascade and coast ranges; California along the northern and coast ranges to Sonoma County; along the western slopes of the Sierra Nevada, where it grows to its greatest size at elevations between 3000° and 7000°; reappearing on the Santa Lucia Mountains of the coast ranges; and on the high mountains in the southwestern part of the state from Santa Barbara County southward usually at elevations of 5000°—7000° above the sea; and on the San Pedro Mártir Mountains in Lower California.

Occasionally planted as an ornamental tree in western Europe and in the eastern states, the Sugar Pine has grown slowly in cultivation and shows little promise of attaining the large size and great beauty which distinguish it in its native forests.

4. Pinus flexilis James. Rocky Mountain White Pine.

_Pinus strobiformis_ Sarg., not Engelm.

Leaves stout, rigid, dark green, marked on all sides by 1—4 rows of stomata, 1½′—3′ long, deciduous in their fifth and sixth years. Flowers: male reddish; female clustered, bright red-purple. Fruit subcylindric, horizontal or slightly declining, green or rarely purple at maturity, 3′—10′ long, with narrow and more or less reflexed scales opening at maturity; seeds compressed, ⅓′—½′ long, dark red-brown mottled with black, with a thick shell produced into a narrow margin, their wings about 1/12′ wide, generally persistent on the scale after the seed falls.

A tree, usually 40°—50°, occasionally 80° high, with a short trunk 2°—5° in diameter, stout long-persistent branches ultimately forming a low wide round-topped head, and stout branchlets orange-green and covered at first with soft fine pubescence, usually soon glabrous and darker colored; at high elevations often a low spreading shrub. Bark of young stems and branches thin, smooth, light gray or silvery white, becoming on old trunks 1′—2′ thick, dark brown or nearly black, and divided by deep fissures into broad ridges broken into nearly square plates covered by small closely appressed scales. Wood light, soft, close-grained, pale clear yellow, turning red with exposure; occasionally manufactured into lumber.

Distribution. Eastern slope of the Rocky Mountains from Alberta to western Texas and westward on mountain ranges at elevations of 5000° to 12,000° to Montana, and southern California, reaching the western slopes of the Sierra Nevada at the head of King’s River near the summit of San Gorgonio Mountain and in Snow Cañon, San Bernardino Range; usually scattered singly or in small groves; forming open forests on the eastern foothills of the Rocky Mountains of Montana and on the ranges of central Nevada; attaining its largest size on those of northern New Mexico and Arizona.

5. Pinus albicaulis Engelm. White Pine.

Leaves stout, rigid, slightly incurved, dark green, marked by 1—3 rows of dorsal stomata, clustered at the ends of the branches, 1½′—2½′ long, persistent for from five to eight years. Flowers opening in July, scarlet. Fruit ripening in August, oval or subglobose, horizontal, sessile, dark purple, 1½′—3′ long, with scales thickened, acute, often armed with stout pointed umbos, remaining closed at maturity; seeds wingless, acute, subcylindric or flattened on one side, ⅓′—½′ long, ⅓′ thick, with a thick dark chestnut-brown hard shell.

A tree, usually 20°—30° or rarely 60° high, generally with a short trunk 2°—4° in diameter, stout very flexible branches, finally often standing nearly erect and forming an open very irregular broad head, and stout dark red-brown or orange-colored branchlets puberulous for two years or sometimes glabrous; at high elevations often a low shrub, with wide-spreading nearly prostrate stems. Bark thin, except near the base of old trunks and broken by narrow fissures into thin narrow brown or creamy white plate-like scales. Wood light, soft, close-grained, brittle, light brown. The large sweet seeds are gathered and eaten by Indians.

Distribution. Alpine slopes and exposed ridges between 5000° and 12,000° elevation, forming the timber-line on many mountain ranges from latitude 53° north in the Rocky Mountains and British Columbia, southward to the Wind River and Salt River Ranges, Wyoming, the mountains of eastern Washington and Oregon, the Cascade Range, the mountains of northern California and the Sierra Nevada to Mt. Whitney.

6. Pinus Balfouriana Balf. Foxtail Pine.

Leaves stout, rigid, dark green and lustrous on the back, pale and marked on the ventral faces by numerous rows of stomata, 1′—1½′ long, persistent for ten or twelve years. Flowers: male dark orange-red; female dark purple. Fruit 3½′—5′ long, with scales armed with minute incurved prickles, dark purple, turning after opening dark red or mahogany color; seeds full and rounded at the apex, compressed at the base, pale, conspicuously mottled with dark purple, ⅓′ long, their wings narrowed and oblique at the apex, about 1′ long and ¼′ wide.

A tree, usually 30°—40° or rarely 90° high, with a trunk generally 1°—2° or rarely 5° in diameter, short stout branches forming an open irregular pyramidal picturesque head, and long rigid more or less spreading puberulous, soon glabrous, dark orange-brown ultimately dark gray-brown or nearly black branchlets, clothed only at the extremities with the long dense brush-like masses of foliage. Bark thin, smooth, and milky white on the stems and branches of young trees, becoming on old trees sometimes ¾′ thick, dark red-brown, deeply divided into broad flat ridges. broken into nearly square plates separating on the surface into small closely appressed scales. Wood light, soft and brittle, pale reddish brown.

Distribution. California, on rocky slopes and ridges, forming scattered groves on Scott Mountain, Siskiyou County, at elevations of 5000°—6000°; on the mountains at the head of the Sacramento River; on Mt. Yolo Bally in the northern Coast Range, and on the southern Sierra Nevada up to elevations of 11,500°, growing here to its largest size and forming an extensive open forest on the Whitney Plateau east of the cañon of Kern River, and at the highest elevations often a low shrub, with wide-spreading prostrate stems.

7. Pinus aristata Engelm. Foxtail Pine. Hickory Pine.

Leaves stout or slender, dark green, lustrous on the back, marked by numerous rows of stomata on the ventral faces, 1′—1½′ long, often deciduous at the end of ten or twelve years or persistent four or five years longer. Flowers male dark orange-red; female dark purple. Fruit 3′—3½′ long, with scales armed with slender incurved brittle prickles nearly ¼′ long, dark purple-brown on the exposed parts, the remainder dull red, opening and scattering their seeds about the 1st of October; seeds nearly oval, compressed, light brown mottled with black, ¼′ long, their wings broadest at the middle, about ⅓′ long and ¼′ wide.

A bushy tree, occasionally 40°—50° high, with a short trunk 2°—3° in diameter, short stout branches in regular whorls while young, in old age growing very irregularly, the upper erect and much longer than the usually pendulous lower branches, and stout light orange-colored, glabrous, or at first puberulous, ultimately dark gray-brown or nearly black branchlets clothed at the ends with long compact brush-like tufts of foliage. Bark thin, smooth, milky white on the stems and branches of young trees, becoming on old trees ½′—¾′ thick, red-brown, and irregularly divided into flat connected ridges separating on the surface into small closely appressed scales. Wood light, soft, not strong, light red; occasionally used for the timbers of mines and for fuel.

Distribution. Rocky or gravelly slopes at the upper limit of tree growth and rarely below 8,000° above the sea from the outer range of the Rocky Mountains of Colorado to those of southern Utah, central and southern Nevada, southeastern California, and the San Francisco peaks of northern Arizona.

8. Pinus cembroides Zucc. Nut Pine. Piñon.

Leaves in 2 or 3-leaved clusters, slender, much incurved, dark green, sometimes marked by rows of stomata on the 3 faces, 1′—2′ long, deciduous irregularly during their third and fourth years. Flowers: male in short crowded clusters, yellow; female dark red. Fruit subglobose, 1′—2′ broad; seeds subcylindric or obscurely triangular, more or less compressed at the pointed apex, full and rounded at base, nearly black on the lower side and dark chestnut-brown on the upper, ½′—¾′ long, the margin of their outer coat adnate to the cone-scale.

A bushy tree, with a short trunk rarely more than a foot in diameter and a broad round-topped head, usually 15°—20° high, stout spreading branches, and slender dark orange-colored branchlets covered at first with matted pale deciduous hairs, dark brown and sometimes nearly black at the end of five or six years; in sheltered cañons on the mountains of Arizona and in Lower California occasionally 50° or 60° tall. Bark about ½′ thick, irregularly divided by remote shallow fissures and separated on the surface into numerous large thin light red-brown scales. Wood light, soft, close-grained, pale clear yellow. The large oily seeds are an important article of food in northern Mexico, and are sold in large quantities in Mexican towns.

Distribution. Mountain ranges of central and southern Arizona, usually only above elevations of 6500°, often covering their upper slopes with open forests; in an isolated station on the Edwards Plateau on uplands and in cañons at the headwaters of the Frio and Nueces Rivers, Edwards and Kerr Counties, Texas; on the Sierra de Laguna, Lower California, and on many of the mountain ranges of northern Mexico; passing into the following varieties differing only in the number of the leaves in the leaf-clusters, and in their thickness.

Pinus cembroides var. Parryana Voss. Nut Pine. Piñon.

_Pinus quadrifolia_ Sudw.

Leaves in 1—5 usually 4-leaved clusters, stout, incurved, pale glaucous green, marked on the three surfaces by numerous rows of stomata, 1¼′—1½′ long, irregularly deciduous, mostly falling in their third year.

A tree, 30°—40° high, with a short trunk occasionally 18′ in diameter, and thick spreading branches forming a compact regularpyramidal or in old age a low round-topped irregular head, and stout branchlets coated at first with soft pubescence, and light orange-brown. Bark ½′—¾′ thick, dark brown tinged with red, and divided by shallow fissures into broad flat connected ridges covered by thick closely appressed plate-like scales. Wood light, soft, close-grained, pale brown or yellow. The seeds form an important article of food for the Indians of Lower California.

Distribution. Arid mesas and low mountain slopes of Lower California southward to the foothills of the San Pedro Mártir Mountains, extending northward across the boundary of California to the desert slopes of the Santa Rosa Mountains, Riverside County, where it is common at elevations of 5000° above the sea-level.

Pinus cembroides var. edulis Voss. Nut Pine. Piñon.

_Pinus edulis_ Engelm.

Leaves in 2 or rarely in 3-leaved clusters, stout, semiterete or triangular, rigid, incurved, dark-green, marked by numerous rows of stomata, ¾′—1½′ long, deciduous during the third or not until the fourth or fifth year, dropping irregularly and sometimes persistent for eight or nine years.

A tree often 40°—50° high with a tall trunk occasionally 2° in diameter and short erect branches forming a narrow head, or frequently with a short divided trunk and a low round-topped head of spreading branches, and thick branchlets orange color during their first and second years, finally becoming light gray or dark brown sometimes tinged with red. Bark ½′—¾′ thick and irregularly divided into connected ridges covered by small closely appressed light brown scales tinged with red or orange color. Wood light, soft, not strong, brittle, pale brown; largely employed for fuel and fencing, and as charcoal used in smelting; in western Texas occasionally sawed into lumber. The seeds form an important article of food among Indians and Mexicans, and are sold in the markets of Colorado and New Mexico.

Distribution. Eastern foothills of the outer ranges of the Rocky Mountains, from northern Colorado (Owl Cañon, Larimer County); to the extreme western part of Oklahoma (near Kenton, Cimarron County, _G. W. Stevens_) and to western Texas, westward to eastern Utah, southwestern Wyoming, and to northern and central Arizona; over the mountains of northern Mexico, and on the San Pedro Mártir Mountains, Lower California; often forming extensive open forests at the eastern base of the Rocky Mountains, on the Colorado plateau, and on many mountain ranges of northern and central Arizona up to elevations of 7000° above the sea.

Pinus cembroides var. monophylla Voss. Nut Pine. Piñon.

_Pinus monophylla_ Torr.

Leaves in 1 or 2-leaved clusters, rigid, incurved, pale glaucous green, marked by 18—20 rows of stomata, usually about 1½′ long, sometimes deciduous during their fourth and fifth seasons, but frequently persistent until their twelfth year.

A tree usually 15°—20°, occasionally 40°—50° high, with a short trunk rarely more than a foot in diameter and often divided near the ground into several spreading stems, short thick branches forming while the tree is young a broad rather compact pyramid, and in old age often pendulous and forming a low round-topped often picturesque head, and stout light orange-colored ultimately dark brown branchlets. Bark about ¾′ thick and divided by deep irregular fissures into narrow connected flat ridges broken on the surface into thin closely appressed light or dark brown scales tinged with red or orange color. Wood light, soft, weak, and brittle; largely used for fuel, and charcoal used in smelting. The seeds supply an important article of food to the Indians of Nevada and California.

Distribution. Dry gravelly slopes and mesas from the western base of the Wasatch Mountains of Utah, westward over the mountain ranges of Nevada to the eastern slopes of the southern Sierra Nevada, and to their western slope at the headwaters of the Tuolumne, Kings and Kern Rivers, and southward to northern Arizona and to the mountains of southern California where it is common on the San Bernardino and San Jacinto Mountains between altitudes of 3500° and 7000°, and on the Sierra del Pinal, Lower California; often forming extensive open forests at elevations between 5000° and 7000°.

PITCH PINES.