ward to the shores of Indian River and those of Tampa Bay, Florida, and westward to
central Minnesota, eastern Iowa (Sharpy County), eastern Nebraska (reported), eastern
Kansas, eastern Oklahoma, and eastern Texas; reappearing on the mountains of southern
Mexico and Central America; common in the eastern and central states; most abundant
and of its largest size on the western slopes of the southern Alleghany Mountains and
in southern Arkansas and eastern Texas.
2. OSTRYA Scop. Hop Hornbeam.
Trees, with scaly bark, heavy hard strong close-grained wood, and acute elongated
winter-buds formed in early summer and covered by numerous imbricated scales, the
inner lengthening after the opening of the bud. Leaves open and concave in the bud;
petioles slender, nearly terete, hairy; stipules strap-shaped to oblong-obovate. Flowers:
staminate in long clustered sessile or short-stalked aments developed in early summer
from lateral buds near the ends of short lateral branchlets of the year and coated while
young with hoary tomentum, naked and conspicuous during the winter, and composed of
3-14 stamens crowded on a pilose receptacle adnate to the base of an ovate concave scale
rounded and abruptly short-pointed at the apex, ciliate on the margins, longer than the
stamens; filaments short, 2-branched, each branch bearing a 1-celled half-anther hairy at
the apex; pistillate in erect lax aments terminal on short leafy branches of the year, in pairs
at the base of an elongated ovate acute leaf-like ciliate scale persistent until midsummer,
each flower inclosed in a hairy sack-like involucre formed by the union of a bract and 2
bractlets; calyx adnate to the ovary, denticulate on the free narrow border. Nut ovoid,
acute, flattened, obscurely longitudinally ribbed, crowned with the remnants of the calyx,
marked at the narrow base by a small circular pale scar, inclosed in the much enlarged pale
membranaceous conspicuously longitudinally veined reticulate-venulose involucres of the
flower, short, pointed and hairy at the apex, hirsute at the base, with sharp rigid stinging
hairs, imbricated into a short strobile fully grown at midsummer, and suspended on a
slender hairy stem.
Ostrya is widely distributed in the northern hemisphere from Nova Scotia to Texas,
northern Arizona, and to the highlands of southern Mexico and Guatemala in the New
World, and through southern Europe and southwestern Asia, and in northern Japan and
on the Island of Quelpart in the Old World. Of the four species now recognized two are
North American.
Ostrya is the classical name of the Hop Hornbeam.
BETULACE.E 203
CONSPECTUS OF THE NORTH AMERICAN SPECIES.
Leaves oblong-lanceolate, acuminate or acute at apex. 1. O. virginiana (A, C).
Leaves elliptic or obovate, acute or rounded at apex. 2. O. Knowltonii (F).
1. Ostrya virginiana K. Koch. Hop Hornbeam. Ironwood.
Leaves oblong-lanceolate, gradually narrowed into a long slender point or acute at apex,
narrowed and rounded, cordate, or wedge-shaped at the often unequal base, sharply serrate,
with slender incurved callous teeth terminating at first in tufts of caducous hairs, when they
unfold light bronze-green, glabrous above and coated below on the midrib and primary
veins with long pale hairs, at maturity thin and extremely tough, dark dull yellow-green
above, light yellow-green and furnished with conspicuous tufts of pale hairs in the axils of
the veins below, 3'-5' long, l^'-2' wide, with a slender midrib impressed and puberulous
above, light yellow and pubescent below, and numerous slender veins forked near the
margins; turning clear yellow before falling in the autumn; petioles hairy about i' long;
stipules rounded and often short-pointed at apex, ciliate on the margins with long pale
hairs, hairy on the back, about \' long and ' wide. Flowers: staminate aments about
' long during their first season, with light red-brown rather loosely imbricated scales nar-
Fig. 192
rowed into a long slender point, becoming when the flowers open 2' long, with broadly
obovate scales rounded and abruptly contracted at apex into a short point, ciliate on the
margins, green tinged with red above the middle, light brown toward the base; pistillate
aments slender, about \' long, on thin hairy stems, their scales lanceolate, acute, light
green, often flushed with red above the middle, hirsute at the apex, decreasing in size from
the lowest. Fruit: nuts \' long, about \' wide, rather abruptly narrowed below the apex,
their involucres in clusters l^'-2' long and f '-!' wide, on slender hairy stems about 1' in
length.
A tree, occasionally 50-60 high, with a short trunk 2 in diameter, usually not more than
20-30 tall, with a trunk 18'-20' thick, long slender branches drooping at the ends and
forming a round-topped or open head frequently 50 across, and slender, very tough branch-
lets, light green, coated with pale appressed hairs when they first appear, becoming light
orange color and very lustrous by midsummer, glabrous, dark red-brown and lustrous during
their first winter, and then growing gradually darker brown and losing their lustre; or cov-
ered like the petioles and peduncles with short erect glandular hairs (var. glandulosa Sarg.)-
204 TREES OF NORTH AMERICA
Winter-buds ovoid, light chestnut-brown, slightly puberulous, ' long. Bark about \'
thick, broken into thick narrow oblong closely appressed plate-like light brown scales
slightly tinged with red on the surface. Wood strong, hard, tough, durable, light brown
tinged with red or often nearly white, with thick pale sapwood of 40-50 layers of annual
growth; used for fence-posts., handles of tools, mallets, and other small articles.
Distribution. Dry gravelly slopes and ridges often in the shade of oaks and other large
trees; Island of Cape Breton and the shores of the Bay of Chaleur, through the valley of
the St. Lawrence River, and along the northern shores of Lake Huron to western Ontario,
Manitoba, Minnesota, eastern North Dakota, the foothills of the Black Hills of South Da-
kota, eastern, northern and northwestern Nebraska, eastern Kansas and Oklahoma, and
southward to northern Florida and eastern Texas; most abundant and of its largest size in
southern Arkansas and in Texas. From Quebec and Ontario to western New England,
western New York, Ohio and in Central Michigan, the glandular form prevails: the two
forms occur in New Jersey, Pennsylvania, Indiana, northern Illinois, southwestern Mis-
souri, Oklahoma, and southward on the high Appalachian Mountains.
2. Ostrya Knowltonii Cov. Ironwood.
Leaves elliptic to obovate, acute or round at apex, gradually narrowed and often un-
equal at the rounded cuneate rarely cordate base, sharply serrate with small triangular
callous teeth, covered with loose pale tomentum when they unfold, at maturity dark
yellow-green and pilose above,, pale and soft-pubescent below, l'-2' long, l'-l' wide, with
a slender yellow midrib slightly raised on the upper side, and slender primary veins con-
nected by obscure reticulate veinlets; turning dull yellow in the autumn before falling;
petioles j'-J' long; stipules pale yellow-green, often tinged with red toward the apex,
%' long, about \' wide. Flowers: staminate aments on stout stalks covered with rufous
tomentum and sometimes \' long, rarely sessile, about \' long during their first season, with
Fig. 193
dark brown puberulous scales gradually contracted into a long slender subulate point,
becoming when the flowers open l'-lj' long, with broadly ovate concave scales ab-
ruptly narrowed into a nearly triangular point, yellow-green near the base, bright red
above the middle; pistillate aments about \' long, with ovate-lanceolate light yellow-green
puberulous scales ciliate on the margins- Fruit: nuts \' long, gradually narrowed at the
apex, their involucres 1' long, nearly glabrous at the apex, sometimes slightly stained
with red toward the base, in clusters l'-l|' long and about f broad, on stems \' in
length.
BETULACE.E 205
A tree 20-30 high, with a trunk 12'-18' in diameter, usually divided 1 or 2 above the
ground into 3 or 4 stout upright stems 4'-5' thick, slender pendulous often much contorted
branches forming a narrow round-topped symmetrical head, and slender branchlets dark
green and coated with hoary tomentum when they first appear, dark red-brown and pu-
bescent during their first summer, becoming light cinnamon-brown, glabrous, and lustrous
in the winter, and ultimately ashy gray. Winter-buds ovoid, dark brownish red, about |'
long. Bark internally bright orange color, ' thick, separating into loose hanging plate-
like scales light gray slightly tinged with red, and l'-2' long and wide. Wood light red-
dish brown, with thin sapwood.
Distribution. On the southern slope of the canon of the Colorado River in Coconino
County, Arizona, at altitudes of 6000-7000 above the sea (Hance trail, seventy miles
north of Flagstaff); in the canon of Oak Creek, south of Flagstaff (P. Lowell); and on
Grand River, Utah (Moab, Grant County, M . E. Jones}.
3. BETULA L. Birch.
Trees, with smooth resinous bark marked by long longitudinal lenticels, often separat-
ing freely into thin papery plates, becoming thick, deeply furrowed, and scaly at the base of
old trunks, short slender branches more or less erect and forming on young trees a narrow
symmetrical pyramidal head, becoming horizontal and often pendulous on older trees,
tough branchlets, short stout spur-like 2-leaved lateral branchlets much roughened by
the crowded leaf-scars of many years, and elongated winter-buds covered by numerous
ovate acute scales, and fully grown and bright green at midsummer. Leaves open and
convex in the bud, often incisely lobed; stipules ovate and acute or oblong-obovate, scarious.
Flowers in 3-flowered cymes, the lateral flowers of the cyme subtended by bractlets adnate
to the base of the scale of the ament; staminate aments long, pendulous, solitary or clus-
tered, appearing in summer or autumn in the axils of the last leaves of a branchlet or near
the ends of short lateral branchlets, erect and naked during the winter, their scales in the
spring broadly ovate, rounded, short-stalked, yellow or orange-color below the middle and
dark chestnut-brown and lustrous above it; staminate flowers composed of amembrana-
ceous 4-lobed calyx often 2-lobed by suppression, the anterior lobe obovate, rounded at apex,
as long as the stamens, much longer than the minute posterior lobe, and of 2 stamens in-
serted on the base of the calyx, with short 2-branched filaments, each branch bearing an
erect half-anther; pistillate aments oblong or cylindric, terminal on the short spur-like
lateral branchlets, their scales closely imbricated, oblong-ovate, 3-lobed, light yellow, often
tinged with red above the middle, accrescent, becoming brown and woody at maturity,
and forming sessile or stalked erect or pendulous short or elongated strobiles usually ripen-
ing in the autumn, deciduous with the nuts from the slender rachis; calyx of the pistillate
flower 0; ovary sessile, compressed, with styles stigmatic at apex. Nut minute, oval or
obovoid, compressed, bearing at the apex the persistent stigmas, marked at the base by
a small pale scar, the outer coat of the shell produced into a marginal wing interrupted at
the apex.
Betula is widely distributed from the Arctic circle to Texas in the New World, and to
southern Europe, the Himalayas, China, and Japan in the Old World, some species form-
ing great forests at the north, or covering high mountain slopes. Of the twenty-eight or
thirty species now recognized twelve are found in North America; of these nine are trees.
Of exotic species the European and Asiatic Betula pendula Roth, in a number of forms is a
common ornamental tree in the northern states, where several of the Birch-trees of eastern
Asia also flourish. Many of the species produce wood valued by the cabinet-maker, or used
in the manufacture of spools, shoe-lasts, and other small articles. The thin layers of the
bark are impervious to water and are used to cover buildings, and for shoes, canoes, and
boxes. The sweet sap provides an agreeable beverage.
Betula is the classical name of the Birch-tree.
206 TREES OF NORTH AMERICA
CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES.
Strobiles oblong-ovoid, nearly sessile, erect, the lateral lobes of their scales broad and slightly
divergent; wing not broader than the nut; leaves with 9-11 pairs of veins; bark of young
branches aromatic.
Leaves heart-shaped or rounded at base; scales of the strobiles glabrous; bark dark
brown, not separating into thin layers. 1. B. lenta (A, C).
Leaves cuneate or slightly heart-shaped at base; scales of the strobiles pubescent; bark
yellow, or silvery white, rarely dull yellowish brown; separating into thin layers.
2. B. lutea (A).
Strobiles oblong or cylindric, erect, spreading or pendant, on slender peduncles; wing
broader than the nut; leaves with 5-9 pairs of veins.
Strobiles oblong, erect, ripening in May or June, their scales pubescent, deeply lobed, the
lateral lobes erect; leaves rhombic-ovate, glaucescent and more or less silky-pubescent
beneath; bark light reddish-brown, separating freely into thin persistent scales.
3. B. nigra (A, C).
Strobiles cylindric, pendant or spreading.
Scales of the strobiles pubescent, with recurved lateral lobes, the middle lobe triangu-
lar, nearly as broad as long; leaves long-pointed; petioles slender, elongated.
Leaves triangular to rhombic, bright green and lustrous; bark chalky white, not
separable into thin layers. 4. B. populifolia (A).
Leaves ovate, cuneate to truncate or rounded at base, dull blue-green; bark white
tinged with pink, lustrous, not easily separable into thin layers.
5. B. cxfirulea (A).
Scales of the strobiles with ascending or spreading lateral lobes, the middle lobe usu-
ally acuminate, longer than broad; leaves acute or acuminate.
Bark separating freely into thin layers; scales of the strobiles glabrous.
Bark creamy white, or in some forms orange-brown; leaves ovate.
6. B. papyrifera (A, B, C, F).
Bark dull reddish brown or nearly white; leaves rhombic to deltoid-ovate.
7. B. alaskana (A, B).
Bark not separable into thin layers, dark brown; scales of the strobiles glabrous
or puberulous; branchlets glandular.
Leaves ovate, acute or acuminate, truncate or rounded at the broad base.
8. B. fontinalis (B, F, G).
Leaves broad-ovate to elliptic, acute, rounded or abruptly short-pointed, cuneate
at base. 9. B. Eastwoodae'(F).
1. Betula lenta L. Cherry Birch. Black Birch.
Leaves ovate to oblong-ovate, acute or acuminate, gradually narrowed and often un-
equal at the cordate or rounded base, sharply serrate with slender incurved teeth, or very
rarely laciniately lobed (f . laciniata Rehdr.), when they unfold light green, coated on the
lower surface with long white silky hairs, and slightly hairy on the upper surface, at ma-
turity thin and membranaceous, dark dull green above, light yellow-green below, with
small tufts of white hairs in the axils of the veins, 2|'-6' long, l%'-3' wide, with a yellow mid-
rib and primary veins prominent and hairy on the lower surface, and obscure reticulate
cross veinlets; turning bright clear yellow late in the autumn; petioles stout, hairy, deeply
grooved on the upper side, f'-l' long; stipules ovate, acute, light green or nearly white,
scarious and ciliate above the middle. Flowers : staminate aments during the winter about
f ' long, nearly |' thick, with ovate acute apiculate scales bright red-brown above the middle
and light brown below it, becoming 3'-4' long; pistillate aments '-f ' long, about f ' thick,
with ovate pale green scales rounded at the apex; styles light pink. Fruit: strobiles ob-
long-ovoid, sessile, erect, glabrous, I'-l^' long, about %' thick; nut obovoid, pointed at
base, rounded at apex, about as broad as its wing.
BETULACE.E
207
A tree, with aromatic bark and leaves, 70-80 high, with a trunk 2-5 in diameter,
slender branches spreading almost at right angles, becoming pendulous toward the ends
and gradually forming a narrow round-topped open graceful head, and branchlets light
green, slightly viscid and pilose when they first appear, soon turning dark orange-brown,
lustrous during the summer, bright red-brown in their first winter, becoming darker and
finally dark dull brown slightly tinged with red. Winter-buds ovoid, acute, about \'
long, with ovate acute light chestnut-brown loosely imbricated scales, those of the inner
ranks becoming \'-\' long. Bark on young stems and branches close, smooth, lustrous,
dark brown tinged with red, and marked by elongated horizontal pale lenticels, becoming
on old trunks '-' thick, dull, deeply furrowed and broken into large thick irregular plates
Fig. 194
covered with closely appressed scales. Wood heavy, very strong and hard, close-grained,
dark brown tinged with red, with thin light brown or yellow sapwood of 70-80 layers of
annual growth; largely used for floors, in the manufacture of furniture and for fuel, and
occasionally in ship and boatbuilding. Sweet birch-oil distilled from the wood and bark is
used for medicinal purposes and for flavoring as a substitute for oil of wintergreen, and
beer is obtained by fermenting the sugary sap.
Distribution. Rich uplands from southern Maine to northwestern Vermont, and eastern
Ohio and southward to northern Delaware and along the Appalachian Mountains up to al-
titudes of 4000 to northern Georgia; in Alabama, and in eastern Kentucky and Tennes-
see; a common forest tree at the north, and of its largest size on the western slopes of the
southern Alleghany Mountains.
X Betula Jackii Schn., a natural hybrid of B. lenta with B. pumila Michx., has appeared
in the Arnold Arboretum.
2. Betula lutea Michx. Yellow Birch. Gray Birch.
Leaves ovate to oblong-ovate, acuminate or acute at apex, gradually narrowed to the
rounded cuneate or rarely heart-shaped usually oblique base, sharply doubly serrate,
when they unfold bronze-green or red, and pilose with long pale hairs above and on the
under side of the midrib and veins, at maturity dull dark green above, yellow-green below,
4^' long, l|'-2' wide, with a stout midrib and primary veins covered below near the
base of the leaf with short pale or rufous hairs; turning clear bright yellow in the autumn;
petioles slender, pale yellow, hairy, i'-l' long; stipules ovate, acute, light green tinged with
pink above the middle, about \' long. Flowers: staminate aments during the winter f'-l'
long, about ' thick, with ovate rounded scales light chestnut-brown and lustrous above
the middle, ciliate on the margins, becoming 3'-8i' long and \' thick; pistillate aments
TREES OF NORTH AMERICA
about f ' long, with acute scales, pale green below, light red and tipped with clusters of long
white hair at apex, and pilose on the back. Fruit: strobiles erect, sessile, short-stalked,
pubescent, !'-!' long, about f thick; nut ellipsoidal to obovoid, about ' long, rather
broader than its wing.
A tree, with slightly aromatic bark and leaves, occasionally 100 high, with a trunk
3-4 in diameter, spreading and more or less pendulous branches forming a broad round-
topped head, and branchlets at first green and covered with long pale hairs, light orange-
brown and pilose during their first summer, becoming glabrous and light brown slightly
tinged with orange, and ultimately dull and darker. Winter-buds about \' long, some-
what viscid and covered with loose pale hairs during the summer, becoming light chest-
nut-brown, acute, and slightly puberulous in winter. Bark of young stems and of the
branches bright silvery gray or light orange color, very lustrous, separating into thin loose
persistent scales more or less rolled on the margins, becoming on old trees \' thick, reddish
Fig. 195
brown, and divided by narrow irregular fissures into large thin plates covered with minute
closely appressed scales, or sometimes dull yellowish brown (B. alleghaniensi* Britt.).
Wood heavy, very strong, hard, close-grained, light brown tinged with red, with thin nearly
white sapwood; largely used for floors, in the manufacture of furniture, button and tassel
moulds, boxes, the hubs of wheels, and for fuel.
Distribution. Moist uplands, and southward often in swamps; one of the largest decid-
uous-leaved trees of northeastern America; Newfoundland and along the northern shores
of the Gulf of St. Lawrence to the valley of Rainy River, and southward to Long Island
(Cold Spring Harbor) and western New York, Pennsylvania, northern Delaware, south-
eastern Ohio, northern Indiana, southwestern Wisconsin, northern, northeastern and cen-
tral Iowa, and from the mountains of Virginia and West Virginia to the highest peaks of
North Carolina and Tennessee at altitudes between 3000 and 5000; very abundant and
of its largest size in the eastern provinces of Canada and in northern New York and New
England; small and rare in southern New England and southward.
X Betula Purpusii Schn. believed to be a natural hybrid of B. lutea with B. pumila
var. glandulifera Regel has been found in Michigan and in Tamarack Swamps in Hennepin,
Pine and Anoka Counties, Minnesota.
3. Betula nigra L. Red Birch. River Birch.
Leaves rhombic-ovate, acute, abruptly or gradually narrowed and cuneate at base,
doubly serrate, and on vigorous young branches often more or less laciniately cut into acute
BETULACEJE 209
doubly serrate lobes, when they unfold light yellow-green and pilose above and coated
below, especially on the midrib and petioles, with thick white tomentum, at maturity
thin and tough, l'-3' long, l'-2' wide, deep green and lustrous above, glabrescent, pu-
bescent or ultimately glabrous below, except on the stout midrib and remote primary
veins; turning dull yellow in the autumn; petioles slender, slightly flattened, tomentose,
about \' long; stipules ovate, rounded or acute at apex, pale green, covered below with
white hairs. Flowers: staminate aments clustered, during the winter about \' long and
T *g thick, with ovate rounded dull chestnut-brown lustrous scales, becoming 2'-3' long
and ' thick; pistillate aments about \ ' long, with bright green ovate scales pubescent on
the back, rounded or acute at apex, and ciliate with long white hairs. Fruit ripening
in May and June; strobiles cylindric, pubescent, \'-\\' long, \' thick, erect on stout tomen-
Fig. 196
tose peduncles \* long; nut ovoid to ellipsoidal, \' in length, pubescent or puberulous at
apex, about as broad as its thin puberulous wing, ciliate on the margin.
A tree, 80-90 high, with a trunk often divided 15-20 above the ground into 2 or
3 slightly diverging limbs, and sometimes 5 in diameter, slender branches forming in old
age a narrow irregular picturesque crown, and branchlets coated at first with thick pale
or slightly rufous tomentum gradually disappearing before winter, becoming dark red and
lustrous, dull red-brown in their second year, and then gradually growing slightly darker
until the bark separates into the thin flakes of the older branches; or often sending up from
the ground a clump of several small spreading stems forming a low bushy tree. Winter-
buds ovoid, acute, about \' long, covered in summer with thick pale tomentum, glabrous
or slightly puberulous, lustrous and bright chestnut-brown in winter, the inner scales
strap-shaped, light brown tinged with red, and coated with pale hairs. Bark on young
stems and large branches thin, lustrous, light reddish brown or silvery gray, marked by
narrow slightly darker longitudinal lenticels, separating freely into large thin papery scales
persistent for several years, and turning back and showing the light pink-brown tints of
the freshly exposed inner layers, becoming at the base of old trunks from f '-!' thick, dark
red-brown, deeply furrowed and broken on the surface into thick closely appressed scales.
Wood light, rather hard, strong, close-grained, light brown, with pale sapwood of 40-50 lay-
ers of annual growth; used in the manufacture of furniture, woodenware, wooden shoes,
and in turnery.
Distribution. Banks of streams, ponds, and swamps, in deep rich soil often inundated
for several weeks at a time; near Manchester, Hillsboro County, New Hampshire, north-
eastern Massachusetts, Long Island, New York, southward to northern Florida through
the region east of the Alleghany Mountains except in the immediate neighborhood of the
210
TREES OF NORTH AMERICA
coast, through the Gulf states to the valley of the Navasota River, Brazos County, Texas,
and through Arkansas, eastern Oklahoma, southeastern Kansas, and Missouri to Tennessee