Crataegus flabellata |
Crataegus orbicularis |
|
---|---|---|
aubépine flabelliforme, fan-leaf hawthorn |
hawthorn, round-leaf hawthorn |
|
Habit | Shrubs or trees, 40–50 dm. | Shrubs, wide-spreading, 20–40 dm. |
Stems | twigs: new growth reddish at first, usually sparsely pubescent, 1-year old deep chestnut brown, older dull gray; thorns on twigs 1-year old shiny, dark brown, stout to slender, 4–6 cm. |
twigs: new growth sparsely pubescent, 1-year old strong mid brown, older dull gray; thorns on twigs straight or more often recurved, slender, 3–5 cm. |
Leaves | petiole 1–2 mm wide, length 40–50% blade, glandular; blade glossy, dark green, broadly elliptic to ovate, 4–7 cm, base cuneate to slightly rounded, lobes 4 or 5 per side, sinuses deep, lobe apex acuminate, margins sharply serrate, teeth gland-tipped, veins 5 or 6 per side, apex acute, abaxial surface glabrous except along veins, adaxial densely appressed-scabrous young, glabrescent. |
petiole 1.2–2 cm, adaxially short-hairy, usually eglandular; blade broadly elliptic to suborbiculate, 5–8 cm, thin, base curved in wider blades, ± attenuate in narrower ones, lobes 3 or 4 per side, short-triangular, margins serrate, teeth very small, except near base, veins 5 or 6(or 7) per side, apex ± subacute, abaxial surface glabrate, veins hairy, adaxial short-appressed-hairy. |
Inflorescences | 5–10-flowered; branches villous; bracteole frequency not recorded, linear. |
10–18-flowered; branches sparsely villous throughout, sometimes glabrate distally; bracteole margins sessile-glandular. |
Flowers | 13–17 mm diam.; hypanthium glabrous or villous at base; sepals 4–5 mm, margins entire, glandular to glandular-serrate, rarely nearly eglandular, apex acute, abaxial pubescence not recorded; stamens 5–10 or 20, anthers usually pink; styles 3–5. |
18 mm diam.; hypanthium glabrate; sepals narrowly triangular, 5–6 mm, margins finely glandular-serrate, abaxial pubescence not recorded; stamens 10, anthers pink; styles 3 or 4. |
Pomes | crimson, ± ellipsoid, 8–10 mm diam., sometimes ± pruinose; sepals spreading or usually erose, not or obscurely elevated; pyrenes 3–5, dorsally deeply grooved. |
in showy infructescences, brick red (mid to late Aug) becoming deep burgundy (Sep), ± oblong, 7–10 mm diam., glabrate; sepals ± erect, wide, length not recorded; pyrenes 3 or 4, sides shallowly pitted or almost plane. |
2n | = 51. |
|
Crataegus flabellata |
Crataegus orbicularis |
|
Phenology | Flowering May–Jun; fruiting Sep–Oct. | Flowering May; fruiting Sep–Oct. |
Habitat | Brush, successional fields, fencelines, woodland edges, open woodlands | Brush, natural hedgerows |
Elevation | 10–200 m (0–700 ft) | 300–400 m (1000–1300 ft) |
Distribution |
CT; MA; ME; NH; NY; VT; NB; NS; ON; QC
|
BC |
Discussion | Crataegus flabellata occurs along the Niagara Escarpment in Ontario, on both sides of Lake Ontario and the St. Lawrence, to New Brunswick and Nova Scotia, and to Massachusetts. Reports for Newfoundland have not been substantiated. Crataegus flabellata is distinctive with its leaf blades glossy dark green, ovate to broadly elliptic, cuneate at the base, and with deep acuminate lobes. Specimens with less glandularity or serration of the sepal margins may resemble C. fluviatilis. In spite of the obvious differences in morphology and range, C. flabellata and C. macrosperma often have been combined by floristicians. From C. chrysocarpa, C. flabellata is distinguished by its shinier, ellipsoid, glabrous fruit, by the usually deeper, acuminate lobes of its glossy, dark green leaves, and by longer, slightly more acute sepals. Typically, the inflorescences and hypanthia of eastern C. chrysocarpa are densely hairy, practically tomentose, unlike C. flabellata with its more sparsely hairy pedicels and glabrous distal hypanthia. It is conceivable that, due to morphological intermediacy and the sympatry of all three species within the range of C. flabellata, this species represents the result of ancient hybridization between C. chrysocarpa and C. macrosperma. Crataegus flabellata is usually divided into two varieties: var. flabellata (10 stamens) and var. grayana (20 stamens), the latter being particularly common in southern Quebec. There appears to be little, if any, other constant differentiating feature. Crataegus crudelis, also from Quebec, is a form recognized by long thorns (to 10 cm). The name Crataegus densiflora Sargent, which pertains to C. flabellata, is illegitimate. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Crataegus orbicularis is known only from within a few miles of Enderby. The species is readily distinguished from sympatric taxa by the unusual pale yellowish green color of the foliage when young, leaf shape, large flowers, and small glabrous pomes with prominent erect sepals. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 567. | FNA vol. 9, p. 507. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Tenuifoliae | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Purpureofructus |
Sibling taxa | ||
Synonyms | Mespilus flabellata, C. crudelis, C. flabellata var. densiflora, C. flabellata var. grayana, C. grayana | |
Name authority | (Bosc ex Spach) K. Koch: Verh. Vereins Beförd. Gartenbaues Königl. Preuss. Staaten, ser. 2, 1: 240. (1853) | J. B. Phipps & O’Kennon: Sida 20: 138, fig. 9. (2002) |
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