Crataegus douglasii

Lindley

Edwards's Bot. Reg. 21: plate 1810. 1835.

Common names: Douglas or black hawthorn
EndemicIllustrated
Synonyms: Crataegus columbiana Howell C. tennowana A. Nelson
Treatment appears in FNA Volume 9. Treatment on page 512. Mentioned on page 493, 494, 511, 513, 514, 599.

Shrubs, 40–80 dm. Stems: 1-year old twigs deep tan to dark mahogany, ± shiny young, older gray to dark gray, often showing brown or alternatively tan-brown eastward; thorns on twigs straight or slightly recurved, deep brown young, (1.5–) 2–3.5 cm. Leaves: petiole 0.7–1.5 cm, pubescent young, slightly glandular; blade usually elliptic to broadly elliptic or subrhombic (elliptic-obovate when lobes very small), 4–7 cm, lobes 2–4 per side, sinuses shallow, LII 10–20%, lobe apex subobtuse to acute, margins coarsely, sharply serrate, teeth small, gland-tipped young, venation craspedodromous, veins 4 or 5 per side, apex acute to obtuse, abaxial surface usually glabrous except on veins, adaxial densely short-appressed-pubescent. Inflorescences 10–25-flowered; branches glabrous; bracteole margins stipitate or sessile-glandular. Flowers 10–15 mm diam.; hypanthium glabrous; sepals broadly triangular, 3–4 mm, margins sparsely glandular, adaxially glabrous; stamens 10, anthers pink; styles 3 or 4. Pomes vinous and usually waxy glaucous young, dull black mature, usually ellipsoid, 6–8 mm diam., glabrous; sepal remnants reflexed, apex obtuse; pyrenes 3 or 4, sides excavated, sometimes only shallowly. 2n = 68.


Phenology: Flowering May–Jun; fruiting Sep–Oct.
Habitat: Brush, old fields, fencerows, woodland edges
Elevation: 50–1600 m

Distribution

V9 862-distribution-map.jpg

Alta., B.C., Ont., Sask., Alaska, Calif., Idaho, Mich., Minn., Mont., Oreg., Wash., Wis.

Discussion

Crataegus douglasii occurs from southern and western British Columbia to the panhandle of Alaska and ranges to northern California and the Rocky Mountains of Idaho, Montana, and southwestern Alberta. Disjunct populations occur farther east in the Cypress Hills (Alberta and Saskatchewan), the Montana montane islands, and around the northern Great Lakes. In western North America, C. douglasii is found mainly near water in drier areas; in more mesic regions, it may occur in open woodlands. In the Great Lakes area, it mainly occurs in old pastures and on fencerows.

Crataegus douglasii is distinguished from C. gaylussacia by having ten stamens and is rather variable in leaf shape and size. The species is distinguished from C. okennonii by the latter usually being taller and typically more erect as well as having a usually straight, single trunk, shorter thorns, ampulliform-orbicular fruit, and often purplish crimson fall foliage. Crataegus castlegarensis is the most similar species, and beyond possessing relatively few to many multiple thorns, it is distinguished from C. douglasii by its hairy hypanthia, pedicels, and, often, fruit, which is orbicular, plump, crimson to purple in late August, ripening to deep purple (sometimes black) at a time when sympatric C. douglasii is fully black.

Selected References

None.

Lower Taxa

None.
... more about "Crataegus douglasii"
short-appressed-pubescent +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
James B. Phipps +
Lindley +
exfoliating +  and plated +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
compound +  and simple +
opposite +  and alternate +
cuneate +
5 cm50 mm <br />0.05 m <br /> (8 cm80 mm <br />0.08 m <br />) +
subrhombic +  and elliptic +
4 cm40 mm <br />0.04 m <br /> (7 cm70 mm <br />0.07 m <br />) +
? (?) +  and ? (?) +
sessile-glandular +  and stipitate +
orange +  and dark gray-brown +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Douglas or black hawthorn +
Alta. +, B.C. +, Ont. +, Sask. +, Alaska +, Calif. +, Idaho +, Mich. +, Minn. +, Mont. +, Oreg. +, Wash. +  and Wis. +
not +  and aggregated +
tan-brown +  and brown +
50–1600 m +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
yellow +  and red or purplish +
0.6 cm6 mm <br />0.006 m <br /> (2 cm20 mm <br />0.02 m <br />) +
usually tan +  and deep mahogany +
pubescent +  and glabrous +
Brush, old fields, fencerows, woodland edges +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
deciduous +
obscure +  and evident +
sessile-glandular +  and stipitate +
subentire +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and basal +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
elliptic +  and circular +
0 (?) +  and 4 (?) +
free +  and distinct +
post-mature +
glandular +  and eglandular +
1.5 cm15 mm <br />0.015 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Flowering May–Jun +  and fruiting Sep–Oct. +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
mature +  and young +
glabrous +  and glaucous +
ellipsoid +
ceraceous +
Edwards's Bot. Reg. +
not arillate +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
persistent +
free +  and distinct +
patent-recurved +  and reflexed +
triangular +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1-50-flowered +  and few-leaved +
Endemic +  and Illustrated +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
elongate +
glabrous +  and tomentose +
Crataegus columbiana +  and C. tennowana +
Crataegus douglasii +
Crataegus (sect. Douglasia) ser. Douglasianae +
species +
craspedodromous +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
straight +
slender +  and stout +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
craspedodromous +  and gland-tipped +
inconspicuous +
1 +  and few +
gray +  and dark gray +
straight +
determinate +
older +, young +  and old +
5 +  and 4 +