Burke: Betula pendula vs. Betula papyrifera

	Betula pendula	Betula papyrifera
	European weeping birch	canoe birch, paper birch, western paper birch, white birch
Habit	Monoecious, deciduous trees to 25 m., trunks usually several, the crowns spreading; bark of mature trees creamy to silvery-white, smooth, peeling in long strips; lenticels dark; branches pendulous, twigs glabrous, dotted with small, resinous glands.	Monoecious, deciduous small tree 15-20 m. tall, the young twigs puberulent and covered with flattened glands that are more or less peltate and not at all resinous; older wood from cherry to chalky-white and peeling.
Leaves	Leaf blades broadly ovate to rhombic, 3-7 cm. long and 2.5-5 cm. wide, the base wedge-shaped, the margins sharply double serrate, the tip acuminate, surfaces glabrous to sparsely pubescent.	Leaves alternate, the blades narrowly ovate to nearly rotund, 4-7 cm. long, once- or twice-serrate, occasionally shallowly lobed, often glabrous on the greener upper surface, pubescent beneath, with tufts of stiff hairs in the axils of the larger lateral veins.
Flowers	Staminate catkins 3 per scale, pendulous; pistillate catkins 3 per scale, erect, cylindric, 2-3.5 cm. long, the scales 3-lobed, the lateral lobes broad and rounded, much longer that the central lobe.	Staminate catkins elongate and pendulous, 1-4 per cluster; pistillate catkins erect, 3-5 cm. long, borne singly, the naked flowers subtended with a 3-lobed bract 5-7 mm. long, with marginal hairs.
Fruits	Samaras with wings much broader than bodies, broadest in the center.	Samara, the wings as broad as the nutlet.

	Betula pendula	Betula papyrifera
Flowering time	April-May	March-May
Habitat	Disturbed areas associated with urban and suburban development where the trees escape from cultivation.	Moist, open to dense woods at low to middle elevations.
Distribution	Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to Oregon; also in northeastern North America. [WildflowerSearch map] [BONAP county map]	Occurring on both sides of the Cascades crest in Washington; Yukon Territory to northeastern Oregon, east across the northern U.S. and Canada to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Introduced from Eurasia	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	B. glandulosa, B. occidentalis, B. papyrifera, B. populifolia, B. pubescens, B. pumila, B. ×utahensis	B. glandulosa, B. occidentalis, B. pendula, B. populifolia, B. pubescens, B. pumila, B. ×utahensis
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	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 papyrifera

European weeping birch

canoe birch, paper birch, western paper birch, white birch

Habit

Monoecious, deciduous trees to 25 m., trunks usually several, the crowns spreading; bark of mature trees creamy to silvery-white, smooth, peeling in long strips; lenticels dark; branches pendulous, twigs glabrous, dotted with small, resinous glands.

Monoecious, deciduous small tree 15-20 m. tall, the young twigs puberulent and covered with flattened glands that are more or less peltate and not at all resinous; older wood from cherry to chalky-white and peeling.

Leaves

Leaf blades broadly ovate to rhombic, 3-7 cm. long and 2.5-5 cm. wide, the base wedge-shaped, the margins sharply double serrate, the tip acuminate, surfaces glabrous to sparsely pubescent.

Leaves alternate, the blades narrowly ovate to nearly rotund, 4-7 cm. long, once- or twice-serrate, occasionally shallowly lobed, often glabrous on the greener upper surface, pubescent beneath, with tufts of stiff hairs in the axils of the larger lateral veins.

Flowers

Staminate catkins 3 per scale, pendulous; pistillate catkins 3 per scale, erect, cylindric, 2-3.5 cm. long, the scales 3-lobed, the lateral lobes broad and rounded, much longer that the central lobe.

Staminate catkins elongate and pendulous, 1-4 per cluster; pistillate catkins erect, 3-5 cm. long, borne singly, the naked flowers subtended with a 3-lobed bract 5-7 mm. long, with marginal hairs.

Fruits

Samaras with wings much broader than bodies, broadest in the center.

Samara, the wings as broad as the nutlet.

Betula pendula

Betula papyrifera

Flowering time

April-May

March-May

Habitat

Disturbed areas associated with urban and suburban development where the trees escape from cultivation.

Moist, open to dense woods at low to middle elevations.

Distribution

Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to Oregon; also in northeastern North America.

[WildflowerSearch map]

[BONAP county map]

Occurring on both sides of the Cascades crest in Washington; Yukon Territory to northeastern Oregon, east across the northern U.S. and Canada to the Atlantic Coast.

[WildflowerSearch map]

[BONAP county map]

Origin

Introduced from Eurasia

Native

Conservation status

Not of concern

Sibling taxa