E-Flora BC: Electronic Atlas of the Flora of British Columbia

Crataegus douglasii Lindl.
black hawthorn
Rosaceae (Rose family)

Introduction to Vascular Plants

© Bryan Kelly-McArthur  Email the photographer   (Photo ID #68847)

E-Flora BC Static Map
Distribution of Crataegus douglasii
Click here to view the full interactive map and legend
Details about map content are available here
New! Click on the map dots to view record details.

Introduction

Black hawthorn is a medium to tall shrub species frequently found in southern British Columbia. It has white flowers with 5 petals that appear in the spring; alternate simple leaves, and straight, stout thorns.

View a key to the hawthorns of the Pacific Coast (from Alaska to California), and species notes, by Jim Phipps.

Species Information

Click on the image below to view an expanded illustration for this species.



General:
Medium to tall shrub 1-7 m tall, with stout, straight thorns 1-2 (3) cm long; bark grey or brownish, rough and scaly.
Leaves:
Alternate, deciduous, egg-shaped to oval, 3-6 cm long, irregularly toothed, the top end often with 5 to 9 shallow lobes, somewhat thick and leathery, dark green above, paler below, nearly smooth to hairy.
Flowers:
Inflorescences short, terminal or axillary clusters; flowers several to many, stalked, 1-1.5 cm across; corollas white, the petals 5, nearly circular, 4-7 mm long; calyces 5-lobed, the lobes triangular, somewhat long-hairy toward the tip; ovaries inferior, smooth to short-curly-hairy, the styles usually 5; stamens 10 to 20.
Fruits:
Berry-like pomes (like miniature apples), globe- to egg-shaped, about 1 cm long, blackish-purple, smooth; stones (nutlets) 2 to 5, 1-seeded.
Notes:
Two varieties occur in BC:

1. Flowers mostly with 10 stamens; ovaries often hairy; leaves often weakly lobed above the middle as well as saw-toothed; plants from largely east of the Coast-Cascade Mtns., the common variety................. var. douglasii

1. Flowers mostly with 20 stamens; ovaries usually smooth; leaves merely 1- to 2-times saw-toothed; plants from west of the Cascade Mtns........................ var. suksdorfii Sarg.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
White
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Black
Present from Spring to Fall
Source:  The USDA

Habitat / Range

Moist to mesic, open rocky slopes, bluffs, streambanks, lakeshores, gullies, thickets, edges of forests in the lowland to montane zones; frequent in S BC north to 56o N; N to S AK, E to ON and S to SD, WY and CA.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Crataegus douglasii

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Minimum

Average

Maximum

Elevation (metres) 1 601 1188
Slope Gradient (%) 0 9 80
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 248 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 4 7
Modal Nutrient Regime
Class
D
Number of field plots
 species was recorded in:
121
Modal BEC Zone Class
IDF
All BEC Zones (# of stations/zone) species was recorded in: BG(14), CDF(5), CWH(10), ICH(36), IDF(36), PP(9), SBS(8)

Ecological Indicator Information

A shade-tolerant/intolerant, submontane to montane, North American deciduous shrub distributed in the Pacific, Cordilleran, and Central regions. Occurs on very moist to wet, nitrogen-rich soils (Moder and Mull humus forms) within boreal. temperate, cool semiarid, and cool mesothermal climates. Sporadic in open­canopy forests on water-receiving sites, scattered in poorly forested, semi-terrestrial communities on water-collecting sites (swamps). Characteristic of nutrient-rich wetlands.

SourceIndicator Plants of Coastal British Columbia (Information applies to coastal locations only)

Climate

The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Crataegus columbiana Howell
Crataegus douglasii var. douglasii Lindl. [superfluous autonym]

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

General References