Crataegus douglasii |
Crataegus reverchonii |
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black hawthorn, Douglas' hawthorn |
Reverchon hawthorn, Reverchon's hawthorn |
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Habit | Shrubs, 40–80 dm. | Shrubs, 10–30(–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. |
twigs: new growth glabrous, 1-year old dark gray; thorns on twigs slightly reflexed, 2-years old blackish, usually stout, 3–6 cm. |
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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 2–5 mm, length 7–11% blade, glabrous, eglandular; blade (on extension shoots) ± orbiculate to broadly elliptic, (on short shoots) ± orbiculate to broadly oblong-elliptic, 2–6 cm, very coriaceous, base broadly cuneate, lobes 0, margins serrulate in distal 1/2, venation semicamptodromous, veins 5 or 6 per side, apex subacute to obtuse, surfaces sparsely hairy young, glabrescent. |
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Inflorescences | 10–25-flowered; branches glabrous; bracteole margins stipitate- or sessile-glandular. |
8–15-flowered; branches usually glabrous; bracteoles linear, small, margins short-stipitate-glandular. |
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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. |
8–12 mm diam.; hypanthium glabrous, sometimes slightly pilose; sepals 4 mm, margins subentire, abaxially glabrous; stamens 10–15(–20), anthers cream, rose, or red; styles (2 or)3–5. |
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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. |
red to orange-red, suborbicular, 10 mm diam., glabrous; sepals persistent, patent or reflexed; pyrenes (1–)3–5. |
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2n | = 68. |
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Crataegus douglasii |
Crataegus reverchonii |
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Phenology | Flowering May–Jun; fruiting Sep–Oct. | |||||||||
Habitat | Brush, old fields, fencerows, woodland edges | |||||||||
Elevation | 50–1600 m (200–5200 ft) | |||||||||
Distribution |
AK; CA; ID; MI; MN; MT; OR; WA; WI; AB; BC; ON; SK
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AL; AR; DE; GA; KS; LA; MO; MS; OK; TN; TX
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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.) |
Varieties 3 (3 in the flora). Crataegus reverchonii is differentiated from C. crus-galli by a greater number of styles and pyrenes (except for var. mohrii) and extension-shoot leaves that tend to be suborbiculate. Distinction from a small-leaved form of C. crus-galli from the Edwards Plateau, Texas, needs elucidation. Crataegus stevensiana is sometimes separated out as a variety or species; however, the complex, unresolved variation makes this distinction moot at the moment. The principal variation within Crataegus reverchonii is between smaller-statured, smaller-leaved, smaller-fruited, more-styled, xeromorphic plants of the southwest (var. reverchonii), and larger-leaved, large-flowered, fewer-styled plants of the mid latitude, eastern United States (var. palmeri). Variety mohrii is intermediate. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 9, p. 512. | FNA vol. 9, p. 537. | ||||||||
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Douglasianae | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Crus-galli | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | C. columbiana, C. tennowana | |||||||||
Name authority | Lindley: Edwards's Bot. Reg. 21: plate 1810. (1835) | Sargent: Trees & Shrubs 1: 55, plate 28. (1903) | ||||||||
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