Frangula alnus |
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alder buckthorn, columnar buckthorn, European alder, European alder-buckthorn, fen buckthorn, glossy buckthorn, glossy false buckthorn, tall hedge buckthorn |
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Habit | Shrubs or small trees, 2–5(–7) m. |
Stems | greenish to brown, sparsely puberulent, glabrescent. |
Leaves | deciduous; petiole 10–19 mm; blade dull green abaxially, glossy darker green adaxially, broadly elliptic-obovate to broadly elliptic or broadly oblong, 4–7(–11) cm, herbaceous, base cuneate to rounded, margins entire, apex rounded to acute or abruptly short-acuminate, abaxial surface sometimes minutely strigose along midveins, adaxial surface glabrous; secondary veins 6–10 pairs. |
Inflorescences | fascicles, sessile, 1–8-flowered. |
Pedicels | 3–10 mm. |
Drupes | black, globose or slightly elongate, 6–8 mm; stones 2(–3). |
Stigmas | 2–3-lobed. |
2n | = 20–26. |
Frangula alnus |
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Phenology | Flowering May–Sep. |
Habitat | Alkaline and acid tamarack, red maple and cedar swamps, peatlands, bogs, fens, disturbed areas, riparian thickets, lakeshores, ditches, fencerows, hedgerows, low woods, beaver meadows. |
Elevation | 10–400 m. (0–1300 ft.) |
Distribution |
CO; CT; IA; ID; IL; IN; KY; MA; ME; MI; MN; NE; NH; NJ; NY; OH; PA; RI; TN; VT; WI; WV; WY; MB; NB; NS; ON; PE; QC; SK; Europe [Introduced in North America; introduced also in Asia (China, Russia), n Africa]
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Discussion | Two horticultural forms of Frangula alnus are widely sold and planted in North America. The cultivar 'Asplenifolia' (F. alnus var. asplenifolia Dippel; fern leaf or cutleaf buckthorn) has linear-oblong leaves with coarsely toothed to incised margins and commonly is grown as a specialty plant. The cultivar 'Columnaris' (tallhedge glossy buckthorn) has a narrow, upright habit and is used in hedging. Both forms were noted by M. H. Brand (http://www.hort.uconn.edu/plants/r/rhafra/rhafra1.html) to spread invasively by seeds. 'Asplenifolia' has been reported as naturalized in Ontario (A. W. Dugal 1989, 1992), Illinois (A. Branhagen, pers. comm.), and Ohio (M. K. Delong et al. 2005). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 59. |
Parent taxa | Rhamnaceae > Frangula |
Sibling taxa | |
Synonyms | Rhamnus frangula |
Name authority | Miller: Gard. Dict. ed. 8, Frangula no. 1. (1768) |
Web links |