Burke: Crataegus monogyna vs. Crataegus douglasii

	Crataegus monogyna	Crataegus douglasii
	English hawthorn, one-seed hawthorn	black hawthorn, Douglas's hawthorn
Habit		Large shrubs or small trees, 1-6 m. tall, armed with stout, straight thorns 1-2 cm. long.
Leaves		Leaf blades obovate, tapered to the petiole, 3-6 cm. long and nearly as broad, weakly lobed, pubescent to glabrous on both surfaces.
Flowers		Flowers few in the leaf axils or terminal; calyx bell-shaped, the 5 lobes triangular, entire, reflexed, 1.5-2.5 mm. long; petals 5, white, orbicular, 5-7 mm. long; stamens 10, styles 5.
Fruits		Berry blackish, glabrous, about 1 cm. long.

	Crataegus monogyna	Crataegus douglasii
Flowering time	April-June	May-June
Habitat	Roadsides, fields, pastures, meadows, thickets, and forest edge and understory at low elevations, often associated with disturbance. Seeds readily dispersed by birds.	Thickets, open forests, forest edges, and riparian zones, from lowlands to middle elevations.
Distribution	Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to California, east to Montana, also in the Great Lakes region and eastern North America. [WildflowerSearch map] [BONAP county map]	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Saskatchewan, Idaho and Montana, also in the Great Lakes region. [WildflowerSearch map] [BONAP county map]
Origin	Introduced from Europe	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	C. castlegarensis, C. chrysocarpa, C. ×cogswellii, C. douglasii, C. gaylussacia, C. laevigata, C. macracantha, C. okanaganensis, C. okennonii, C. phaenopyrum, C. phippsii, C. tenuior	C. castlegarensis, C. chrysocarpa, C. ×cogswellii, C. gaylussacia, C. laevigata, C. macracantha, C. monogyna, C. okanaganensis, C. okennonii, C. phaenopyrum, C. phippsii, C. tenuior
Subordinate taxa	C. monogyna var. monogyna
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Crataegus monogyna

Crataegus douglasii

English hawthorn, one-seed hawthorn

black hawthorn, Douglas's hawthorn

Habit

Large shrubs or small trees, 1-6 m. tall, armed with stout, straight thorns 1-2 cm. long.

Leaves

Leaf blades obovate, tapered to the petiole, 3-6 cm. long and nearly as broad, weakly lobed, pubescent to glabrous on both surfaces.

Flowers

Flowers few in the leaf axils or terminal;

calyx bell-shaped, the 5 lobes triangular, entire, reflexed, 1.5-2.5 mm. long;

petals 5, white, orbicular, 5-7 mm. long;

stamens 10, styles 5.

Fruits

Berry blackish, glabrous, about 1 cm. long.

Crataegus monogyna

Crataegus douglasii

Flowering time

April-June

May-June

Habitat

Roadsides, fields, pastures, meadows, thickets, and forest edge and understory at low elevations, often associated with disturbance. Seeds readily dispersed by birds.

Thickets, open forests, forest edges, and riparian zones, from lowlands to middle elevations.

Distribution

Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to California, east to Montana, also in the Great Lakes region and eastern North America.

[WildflowerSearch map]

[BONAP county map]

Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Saskatchewan, Idaho and Montana, also in the Great Lakes region.

[WildflowerSearch map]

[BONAP county map]

Origin

Introduced from Europe

Native

Conservation status

Not of concern

Sibling taxa