My Invasive Pigments project has expanded to include species native to North America but considered invasive elsewhere. August is a great time to gather berries and other fruits, and (with the help of Peter Del Tredici’s Wild Urban Plants of the Northeast) I’ve discovered several fruit bearing plants that are native here but considered invaders in other locales.
The all-American Black Cherry (Prunus serotina) has a native range extending across the eastern half of North America, from the mountains of Guatemala in the south to Nova Scotia in the north. The species has been spreading rapidly in Europe over the last century. Around 1630, the first specimen arrived in Paris, brought intentionally as an ornamental tree for gardens and boulevards. It was later tested for timber production in Central Europe, but never really worked out. It did, however, manage to become naturalized, and by the early 20th century it had begun its spread across the European landscape.
Prunus serotina is described as a pioneer species, meaning it tends to be among the first to move into compromised or disturbed habitats. In the Eastern United States it is often found growing in vacant lots, empty fields, and along the unkempt borders of suburban parks. Topping out at around 40 meters (130 feet), it can be a commanding presence in the urban and suburban ecosystem. In its invasive range it tends to be smaller (no more than 20 meters) and often malformed due to fungal infection. According to NOBANIS (Northern European and Baltic Network on Invasive Species), the species is most problematic in Central Europe, where it’s blamed for reducing biodiversity in coniferous and mixed coniferous forests and for encroaching on delicate ecosystems like heath, grasslands, and bogs. It’s commonly known in Germany as the “forest pest” but evidence of its deleterious impact is not generally well documented. The whole plant is known to contain cyanic acid (as do other drupe producing trees like apricots and plums) which can be poisonous to livestock.
Below, a topographical exploration of the spread of Prunus serotina. Native and invasive ranges are painted with pigments extracted from the fruit of samples gathered at Great Kills Park in Staten Island. See a larger version here.