OregonFlora: Betula pendula

	Betula pendula
	European white birch
Habit	Trees to 25 m; bark white with dark lenticels, peeling off in papery sheets.
Twigs	pendent, glabrous or very finely puberulent, sometimes glutinous when young but without evident resin-blisters.
Leaves	blades triangular to triangular-ovate; thin, green above, pale green beneath, 41–57 × 31–50 mm, bases obtuse or truncate; margins irregularly serrate; teeth (12)15–27 on each side; acute; each side with 5–7 large teeth, 2–3 mm, terminating main veins; other teeth very much smaller; secondary veins 5–7 on each side; tips strongly acuminate; surfaces glabrous; petioles 15–25 mm, glabrous or very finely puberulent.
Fruits	broadly winged; wing broader than seed.
Pistillate catkins	25–35 mm; bracts with a broad, triangular or ovate central lobe and very broad lateral lobes.

	Betula pendula
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	River bottoms, forests, disturbed areas. Flowering Apr–May. 0–900 m. Casc, Est, Sisk, WV. WA; north to British Columbia, east to MA; Asia, Europe. Exotic. Weeping birch is a popular shade tree, widely planted in western Oregon, and occasionally escaping. It differs from all our native species in its pendent twigs and its triangular to triangular-ovate, strongly acuminate leaves. Plants with deeply laciniate leaves are sometimes cultivated, but this morphology is not known from escaped plants.
Source	Flora of Oregon, volume 2, page 383 Alan Whittemore
Sibling taxa	B. glandulosa, B. occidentalis, B. papyrifera, B. pumila
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Betula pendula

European white birch

Habit

Trees to 25 m; bark white with dark lenticels, peeling off in papery sheets.

Twigs

pendent, glabrous or very finely puberulent, sometimes glutinous when young but without evident resin-blisters.

Leaves

blades triangular to triangular-ovate; thin, green above, pale green beneath, 41–57 × 31–50 mm, bases obtuse or truncate;

margins irregularly serrate;

teeth (12)15–27 on each side; acute; each side with 5–7 large teeth, 2–3 mm, terminating main veins; other teeth very much smaller;

secondary veins 5–7 on each side;

tips strongly acuminate;

surfaces glabrous;

petioles 15–25 mm, glabrous or very finely puberulent.

Fruits

broadly winged;

wing broader than seed.

Pistillate catkins

25–35 mm;

bracts with a broad, triangular or ovate central lobe and very broad lateral lobes.

Betula pendula

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

River bottoms, forests, disturbed areas. Flowering Apr–May. 0–900 m. Casc, Est, Sisk, WV. WA; north to British Columbia, east to MA; Asia, Europe. Exotic.

Weeping birch is a popular shade tree, widely planted in western Oregon, and occasionally escaping. It differs from all our native species in its pendent twigs and its triangular to triangular-ovate, strongly acuminate leaves. Plants with deeply laciniate leaves are sometimes cultivated, but this morphology is not known from escaped plants.

Source

Flora of Oregon, volume 2, page 383
Alan Whittemore

Sibling taxa

B. glandulosa, B. occidentalis, B. papyrifera, B. pumila

Web links