Crataegus douglasii |
Crataegus harbisonii |
|
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black hawthorn, Douglas' hawthorn |
Harbison hawthorn, Harbison's hawthorn |
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Habit | Shrubs, 40–80 dm. | Shrubs or trees, 50–80 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 sparsely pilose, 1-year old chestnut brown, becoming smooth; thorns on twigs frequent, 2-years old glossy, dark brown or nearly black, stout, 3–4 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 15–20% blade, sparsely pilose, gland-dotted; blade shiny green, broadly elliptic to ovate, 4–7 cm, base cuneate, lobes 0 or 1–4 per side, sometimes apiculi, sinuses very shallow, margins doubly serrate, 5 teeth per cm, teeth 2 mm, gland-tipped early, veins 6 or 7 per side, apex acute, abaxial surface pubescent on veins mature, adaxial appressed-pubescent young. |
Inflorescences | 10–25-flowered; branches glabrous; bracteole margins stipitate- or sessile-glandular. |
5–12-flowered, arising subterminally from perennial short shoots, also frequently on leafy side shoots of season lateral to extension shoots; branches pilose; bracteoles semipersistent, ligulate, 7–18 mm, subherbaceous, margins glandular-pectinate to glandular-serrate. |
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. |
20–25 mm diam.; hypanthium pubescent; sepals lanceolate, margins glandular-laciniate; stamens 20, anthers cream to light yellow; styles 3–5. |
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. |
orange-red to red, 12–22 mm diam., pubescent; sepals patent-reflexed; pyrenes 3–5. |
2n | = 68. |
= 68. |
Crataegus douglasii |
Crataegus harbisonii |
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Phenology | Flowering May–Jun; fruiting Sep–Oct. | Flowering early May; fruiting Sep–Nov. |
Habitat | Brush, old fields, fencerows, woodland edges | Wooded hills, creekside brush |
Elevation | 50–1600 m (200–5200 ft) | 0–200 m (0–700 ft) |
Distribution |
AK; CA; ID; MI; MN; MT; OR; WA; WI; AB; BC; ON; SK
|
AL; TN |
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 harbisonii is rare and is similar both to C. ashei and C. triflora and could perhaps be thought of as a particularly robust form of C. ashei; however, it is perhaps more likely of hybrid origin between these species. The most significant similarity to C. triflora (ser. Triflorae) is an ability to produce inflorescences on shoots of the season lateral to extension shoots. Nevertheless, it is easily distinguished from C. triflora by characteristics of growth habit, by its smaller flowers (except in the Louisiana and some Mississippi forms of C. triflora) with fewer stamens, by the more coriaceous leaves with larger and more distant teeth, by having among the most persistent bracteoles in the genus, a feature that led to the creation of ser. Bracteatae. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 512. | FNA vol. 9, p. 608. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Douglasianae | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Bracteatae |
Sibling taxa | ||
Synonyms | C. columbiana, C. tennowana | SELECTEDREFERENCE |
Name authority | Lindley: Edwards's Bot. Reg. 21: plate 1810. (1835) | Beadle: Bot. Gaz. 28: 413. (1899) |
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