Crataegus douglasii |
Crataegus oakesiana |
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black hawthorn, Douglas' hawthorn |
Oakes' hawthorn |
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Habit | Shrubs, 40–80 dm. | Shrubs, 60 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. |
twigs: new growth green, glabrous, 1-year old shiny, mid brown, older deep gray; thorns on twigs frequent, recurved, 1-year old shiny reddish to blackish brown, slender to moderately thick, 2–4.5 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. |
petiole length 40% blade, glabrous, densely glandular; blade broadly ovate to oblong-ovate or broadly elliptic, smaller sometimes ± rhombic, 3–5 cm, on extension shoots larger, often suborbiculate, thin to chartaceous, base cuneate to broadly cuneate or ± rounded, lobes 4 or 5 per side, sinuses shallow, lobe apex triangular, margins serrate teeth numerous, small, veins 6–8 per side, apex acute, abaxial surface glabrous, adaxial densely appressed-scabrous young, glabrescent. |
Inflorescences | 10–25-flowered; branches glabrous; bracteole margins stipitate- or sessile-glandular. |
6–10-flowered; branches pilose; bracteoles linear, membranous, margins 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. |
16 mm diam.; hypanthium pubescent; sepals narrowly triangular, 6 mm, margins glandular, sometimes barely glandular-serrate, abaxially glabrous; stamens 20, anthers cream; 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. |
reddish, broadly ellipsoid to suborbicular, 11–14 mm diam., smooth, glabrous; sepals spreading, often erose; pyrenes 3 or 4. |
2n | = 68. |
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Crataegus douglasii |
Crataegus oakesiana |
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Phenology | Flowering May–Jun; fruiting Sep–Oct. | Flowering May; fruiting Sep–Oct. |
Habitat | Brush, old fields, fencerows, woodland edges | Rocky outcrops |
Elevation | 50–1600 m (200–5200 ft) | 100–200 m (300–700 ft) |
Distribution |
AK; CA; ID; MI; MN; MT; OR; WA; WI; AB; BC; ON; SK
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VT |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Crataegus oakesiana is not very different from C. chrysocarpa var. vigintistamina, differing primarily in its suborbiculate extension-shoot leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 512. | FNA vol. 9, p. 601. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Douglasianae | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Rotundifoliae |
Sibling taxa | ||
Synonyms | C. columbiana, C. tennowana | |
Name authority | Lindley: Edwards's Bot. Reg. 21: plate 1810. (1835) | Eggleston: Torreya 7: 35. (1907) |
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