The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

cherry birch, sweet birch

bouleau mineur, dwarf birch, dwarf white birch

Habit Trees, to 20 m; trunks tall, straight, crowns narrow. Shrubs, erect, irregularly spreading, or depressed, to 5 m. Bark dark, reddish brown, smooth, close, not readily exfoliating; lenticels pale, horizontally expanded.
Bark

of mature trunks and branches light grayish brown to dark brown or nearly black, smooth, close, furrowed and broken into shallow scales with age.

Twigs

with taste and odor of wintergreen when crushed, glabrous to sparsely pubescent, usually covered with small resinous glands.

without odor and taste of wintergreen, glabrous to sparsely pubescent, often dotted with resinous glands.

Leaf

blade ovate to oblong-ovate with 12–18 pairs of lateral veins, 5–10 × 3–6 cm, base rounded to cordate, margins finely and sharply serrate or obscurely doubly serrate, teeth fine, sharp, apex acuminate;

surfaces abaxially mostly glabrous, except sparsely pubescent along major veins and in vein axils, often with scattered, minute, resinous glands.

blade ovate with 2–6 pairs of lateral veins, 1.5–5.5(–8) × 1.5–3(–5) cm, base rounded or cuneate to truncate, margins coarsely doubly serrate, teeth obtuse to rather sharp, toothed nearly to base, apex acute to obtuse;

surfaces abaxially glabrous to moderately pubescent, usually more densely pubescent along major veins, often covered with small resinous glands.

Infructescences

erect, ovoid to nearly globose, 1.5–4 × 1.5–2.5 cm, usually remaining intact for a period after release of fruits in fall;

scales mostly glabrous, lobes diverging at or proximal to middle, central lobe short, cuneate, lateral lobes extended to slightly ascending, longer and broader than central lobe.

erect, cylindric 1–3 × 0.5–1 cm, shattering with fruits in fall;

scales glabrous to moderately pubescent, lobes diverging at middle, central lobe elongate, apex obtuse, lateral lobes ascending, as long as to nearly shorter and broader than central lobe.

Samaras

with wings narrower than body, broadest near center, not extended beyond body apically.

with wings equal to or broader than body, broadest near summit, extending beyond body apically.

2n

= 28.

= 56.

Betula lenta

Betula minor

Phenology Flowering late spring. Flowering late spring.
Habitat Rich, moist, cool forests, especially on protected slopes, to rockier, more exposed sites Rocky slopes, barrens, and subalpine summits
Elevation 0–1500 m (0–4900 ft) 1000–2000 m (3300–6600 ft)
Distribution
from FNA
AL; CT; GA; KY; MA; MD; ME; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
ME; NH; NY; NB; NF; NS; ON; QC
[BONAP county map]
Discussion

Betula lenta is a dominant tree in the northern hardwood forests of the northern Appalachians and a valuable source of timber. It was formerly the chief commercial source of wintergreen oil (methyl salicylate), which is distilled from its wood. Betula lenta is most easily separated from B. alleghaniensis by its close bark and the glabrous scales of infructescences.

Native Americans used Betula lenta medicinally to treat dysentery, colds, diarrhea, fevers, soreness, and milky urine, and as a spring tonic.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The origin and relationships of this small birch have not been adequately determined. Betula minor resembles B. pubescens (as B. odorata Bechstein) of Greenland and northern Europe (M. L. Fernald 1950), and it has been combined into that species (A. Löve and D. Löve 1966). Northern and maritime populations of the complex have often been segregated as a separate species (B. borealis Spach sensu M. L. Fernald 1950; B. saxophila of E. Lepage 1976); the name B. minor has been mostly restricted to the subalpine form of northern Appalachian peaks. These two taxa actually constitute a single, somewhat variable, morphologic entity; they are indistinguishable by the minor character differences that have been used to separate them in the past. Because Spach's type of B. borealis consists of material of B. pumila (B. Boivin 1967b), that name must be rejected for this species.

Further complicating matters, E. Lepage (1976) concluded that the type of Betula minor represents a hybrid between individuals of the dwarf species and B. papyrifera, and on that basis, following nomenclatural rules, he renamed the dwarf species B. saxophila, retaining the name B. minor for the hybrid. Leaf shapes and other visible characters of the type fall easily within the limits of variation of B. saxophila, however, and the group is considered here to consist of a single entity, designated by the older name B. minor.

At least in the Adirondacks, Betula minor usually occurs near populations of B. cordifolia and B. glandulosa, and it has frequently been suggested (e.g., E. Hultén 1968; E. Lepage 1976; J. J. Furlow 1990) that it may have originated through hybridization between these species (perhaps followed by polyploidy). The northern populations may similarly consist of a hybrid swarm involving B. papyrifera or B. cordifolia and B. glandulosa. Critical examination of the entire complex, including experimental studies of the patterns of hybridization present, are necessary to unravel its problems satisfactorily.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 3. FNA vol. 3.
Parent taxa Betulaceae > subfam. Betuloideae > Betula Betulaceae > subfam. Betuloideae > Betula
Sibling taxa
B. alleghaniensis, B. cordifolia, B. glandulosa, B. kenaica, B. michauxii, B. minor, B. murrayana, B. nana, B. neoalaskana, B. nigra, B. occidentalis, B. papyrifera, B. pendula, B. populifolia, B. pubescens, B. pumila, B. uber
B. alleghaniensis, B. cordifolia, B. glandulosa, B. kenaica, B. lenta, B. michauxii, B. murrayana, B. nana, B. neoalaskana, B. nigra, B. occidentalis, B. papyrifera, B. pendula, B. populifolia, B. pubescens, B. pumila, B. uber
Synonyms B. papyracea var. minor, B. pubescens subsp. minor, B. saxophila
Name authority Linnaeus: Sp. Pl. 2: 983. (1753) (Tuckerman) Fernald: Rhodora 47: 306. (1945)
Web links