Rhamnus cathartica, the European buckthorn,[3]common buckthorn, purging buckthorn, or just buckthorn, is a species of small tree in the flowering plant family Rhamnaceae. It is native to Europe, northwest Africa and western Asia, from the central British Isles south to Morocco, and east to Kyrgyzstan.[4] It was introduced to North America as an ornamental shrub in the early 19th century or perhaps before, and is now naturalized in the northern half of the continent, and is classified as an invasive plant in several US states[5][6][7] and in Ontario, Canada.[8]
^Torrey, J. (1824). A flora of the northern and middle sections of the United States: or, a systematic arrangement of all the plants hitherto discovered in the United States north of Virginia. Vol 1. New York:T. and J. Swords, pp. 513
^Possessky, S. L., Williams, C. E., Moriarty, W. J. (2000). "Glossy Buckthorn, Rhamnus frangula L.: A threat to riparian plant communities of the northern Allegheny plateau (USA)". Natural Areas Journal. 20: 290–292.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^"Rhamnus cathartica". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.