Betula cordifolia

Regel

Nouv. Mém. Soc. Imp. Naturalistes Moscou 13(2): 86. 1861.

Common names: Heartleaf birch mountain white birch bouleau &agrave feuilles cordées bouleau blanc
Endemic
Synonyms: Betula alba var. cordifolia (Regel) Fernald Betula papyrifera var. cordifolia (Regel) Fernald
Treatment appears in FNA Volume 3.

Trees or shrubs, large, irregular, to 20 m; trunks often several, trees with narrow crowns. Bark of young trunks and branches dark reddish-brown, close, in maturity reddish white to reddish tan or bronze, exfoliating in paper-thin sheets; lenticels dark, horizontally expanded. Twigs glabrous to sparsely pubescent, often covered with conspicuous, warty, resinous glands. Leaf-blade narrowly ovate to ovate with 9–12 pairs of lateral-veins, 6–10 (–14) × 4–8 cm, base usually cordate, rarely rounded, margins coarsely or irregularly doubly serrate, apex short-acuminate, abaxially sparsely to moderately pubescent, sometimes velutinous or tomentose along major veins and in vein-axils, covered with minute, resinous glands. Infructescences pendulous or nearly pendulous, cylindric, 2.5–5.5 × 0.6–1 cm, shattering with fruits in fall; scales glabrous to moderately pubescent, lobes diverging proximal to middle, central lobe elongate, obtuse, lateral lobes ascending, shorter and slightly broader than central lobe. Samaras with wings broader than body, broadest near summit, extended beyond body apically. 2n = 28, 56.


Phenology: Flowering late spring.
Habitat: Moist, rocky slopes or rich, open forest
Elevation: 800–2000 m

Distribution

V3 92-distribution-map.gif

St. Pierre and Miquelon, N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Maine, Mass., Mich., Minn., N.H., N.Y., N.C., Pa., Vt., Va., W.Va., Wis.

Discussion

Betula cordifolia has been reported from Connecticut; I have not seen specimens.

In recent years Betula cordifolia has usually been treated as a variety of B. papyrifera, and perhaps it should be considered an ecological race of that species. It differs from B. papyrifera in polyploid level (diploid and tetraploid in B. cordifolia versus tetraploid, pentaploid, and hexaploid in B. papyrifera) and in vegetative characters, including the number of lateral veins of leaves and the color of bark (W. H. Brittain and W. F. Grant 1967; P. E. DeHond and C. S. Campbell 1989). In the Adirondacks, B. cordifolia and B. papyrifera occur in rather distinct ecological zones (B. cordifolia mostly above 800 m and B. papyrifera generally below this elevation). The species does not appear to occur as far west (Iowa) as stated by M. L. Fernald (1950).

Selected References

None.

Lower Taxa

None.

"slightly broader" is not a number."broadest" is not a number. "broader" is not a number.

... more about "Betula cordifolia"
tomentose +, velutinous +  and pubescent +
short-acuminate +
John J. Furlow +
tanniferous +  and furrowed +
reddish white +  and reddish tan or bronze +
exfoliating +
rounded +  and cordate +
2 +  and 3 +
terete +
slender +
staminate +  and pistillate +
solitary +  and in small racemose clusters +
ovoid +  and cylindric +
expanding +
obtuse +  and elongate +
Heartleaf birch +, mountain white birch +, bouleau &agrave +, feuilles cordées +  and bouleau blanc +
multibracteate +
St. Pierre and Miquelon +, N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Maine +, Mass. +, Mich. +, Minn. +, N.H. +, N.Y. +, N.C. +, Pa. +, Vt. +, Va. +, W.Va. +  and Wis. +
800–2000 m +
pistillate +  and staminate +
expanding +
conspicuous +
Moist, rocky slopes or rich, open forest +
2.5 cm25 mm <br />0.025 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
pendulous;pendulous +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
membranaceous +
10 cm100 mm <br />0.1 m <br /> (14 cm140 mm <br />0.14 m <br />) +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
narrowly ovate;ovate +
proximal +  and middle +
not obvious +  and defined +
membranaceous +
Flowering late spring. +
2(-3)-carpellate +
Nouv. Mém. Soc. Imp. Naturalistes Moscou +
1-seeded +  and 2-winged +
extended +
crowded +  and imbricate +
deciduous +
glabrous +  and moderately pubescent +
(1-)3-lobed +
expanding +
not woody +  and leathery +
paper-thin +
2 +  and 3 +
nearly +  and distinct +
glabrous;tomentose +
Betula alba var. cordifolia +  and Betula papyrifera var. cordifolia +
Betula cordifolia +
species +
excurrent +  and branching +
glabrous +  and sparsely pubescent +
differentiated +
tree +  and shrub +
broader +
tanniferous +
light +, nearly white +  and reddish-brown +
soft +  and hard +