Crataegus phaenopyrum |
Crataegus atrovirens |
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Washington hawthorn, Washington thorn |
dark-green hawthorn, hawthorn |
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Habit | Trees, 40–100 dm. | Shrubs, 20–50 dm. |
Stems | 3-year old twigs shiny, deep reddish brown, older dark gray; thorns on twigs ± straight, 2–5 cm. |
multiple, suberect to erect; twigs: new growth pubescent, 1-year old glossy brown, older dark gray; bark on 2–5 cm thick branches gray-brown; thorns on twigs ± straight to very slightly curved, ± slender, 3–5 cm, 2-years old dark brown, black at tip, older deep gray. |
Leaves | petiole slender, sometimes both abaxially and adaxially short rusty-tomentose, eglandular; blade broadly to narrowly deltate, 3–6 cm, base truncate to rarely cuneate or cordate, sometimes very shallowly so, lobes palmately or pinnately 2(or 3) per side, margins serrulate, veins 6 or 7(or 8) per side (to sinuses), apex acute, surfaces glabrous. |
petiole length 15–20% blade, sparsely or densely (in adaxial sulcus mature) hairy, eglandular or sparsely small glandular mainly distally; blade dark green (in fall turning bronze-brown), matte, narrowly ovate to broadly elliptic-rhombic or broadly elliptic, 4–6(–7) cm, subcoriaceous, base cuneate, lobes 3 or 4 per side, small, max LII ca. 10%, lobe apex acute, margins serrulate, minutely glandular at apices, veins 3–5 per side, apex acute to subacute, matte, abaxial surface glabrate, vein pubescence not recorded, adaxial scabrous hairy, glabrescent. |
Inflorescences | 15–30-flowered, flowers strong-smelling; branches glabrous; bracteole margins stipitate-glandular. |
12–20-flowered; branches densely spreading-pubescent; bracteoles narrow but widened distally, margins densely glandular. |
Flowers | 10–12 mm diam.; hypanthium glabrous; sepals 2 mm; stamens 20, anthers ivory; styles 3(or 4). |
10–14 mm diam.; hypanthium pubescent; sepals narrowly triangular, 4–5 mm, margins strongly glandular-serrate, abaxial pubescence not recorded; stamens 10(–20), anthers pink; styles 2 or 3. |
Pomes | burgundy (late Aug), blackish purple (Sep), dull, ± ovoid, 13–15 × 10 mm, hairy; flesh soft orange; sepals suberect, wide, 4–6 mm; pyrenes 2 or 3, sides pitted. |
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2n | = 51, 68. |
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Crataegus phaenopyrum |
Crataegus atrovirens |
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Phenology | Flowering Jun; fruiting Sep–Nov. | Flowering May; fruiting Sep–Oct. |
Habitat | Woodland edges, gaps, scrub, damp locations | Natural hedgerows, brush in valleys, dry habitats |
Elevation | 10–300 m (0–1000 ft) | 300–500 m (1000–1600 ft) |
Distribution |
AR; DE; FL; GA; IL; IN; KY; LA; MD; MI; MO; MS; NC; OH; OR; PA; SC; TN; VA; WA; WV; ON
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BC |
Discussion | Crataegus phaenopyrum has a wide native range across the middle latitudes of the United States from Missouri to Maryland and southward but is not particularly abundant. In the northern and western states and Ontario, it is introduced. All alleged specimens for Alabama proved to be wrongly identified (J. B. Phipps 1998). The flowering season of the Washington thorn is the latest of all North American hawthorns. The species is one of the most widely planted ornamentals in the genus, being elegantly treelike and possessing beautiful, remarkably rust-resistant foliage at all seasons as well as attractive flowers and fruit. Several cultivars are known. Crataegus cordata (Miller) Aiton 1789 (= Mespilus cordata Miller 1757) was commonly used for C. phaenopyrum until the early 20th century (J. B. Phipps 1999). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Crataegus atrovirens is known from the northern Okanagan, where it is locally common to abundant. One of its most notable characteristics are the unusually large glands on the leaf teeth. It also has smallish flowers for its series. Of species known to date from this region, C. shuswapensis is the one most likely to be confused with C. atrovirens. The mature fruit and the growth habit of C. shuswapensis are similar, but that species has leaves more sharply lobed, glabrous inflorescences, sometimes 15–18 stamens per flower, redder fruit in the fourth week of August, much smaller, less prominent fruiting sepals, whose margins, rather than being serrato-laciniate, are minutely glandular. Crataegus atrovirens also has similarities to C. okanaganensis; it is easily differentiated in the field by the usually much longer thorns, smaller flowers with pink anthers, and much darker fruit in late August. Compared to C. orbicularis, the fruit of C. atrovirens is also conspicuously larger; it is soft and ripe in the fourth week of August when the former is hard but not ripe. The erect, multi-trunked habit is also somewhat distinctive. It is a dull hawthorn, somber in appearance, contrasting markedly with more colorful congeners such as C. okanaganensis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 499. | FNA vol. 9, p. 506. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Crataegus > ser. Cordatae | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Purpureofructus |
Sibling taxa | ||
Synonyms | Mespilus phaenopyrum, C. youngii | |
Name authority | (Linnaeus f.) Medikus: Gesch. Bot., 84. (1793) | J. B. Phipps & O’Kennon: Sida 20: 141, fig. 10. (2002) |
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