Heracleum sosnowskyi in Bulgaria
In 2017, the alien species Heracleum sosnowskyi (EPPO A2 List and EU Invasive Alien Species of Union Concern) was reported for the first time in Bulgaria, though additional research proved that this was a misidentification and the plants belonged to H. mantegazzianum (EPPO List of Invasive Alien Plants and EU Invasive Alien Species of Union Concern). However, during further field surveys conducted in the summer months in 2018, H. sosnowskyi was positively identified in the Western Rhodopi Mountains. Notes on the species include that it flowers in June and July with the fruits ripening in July-August. It is easily distinguishable from native Heracleum species (H. angustisectum, H. sibiricum, H. ternatum and H. verticillatum) by the larger basal and lower cauline leaves, larger compound umbels and the short ovate or elliptic leaves. In Bulgaria, H. sosnowskyi has been found on the edge of agricultural fields, along the side of roads, and in urban environments. In some locations, hundreds of fruiting plants have been observed. Following interviews with local farmers in the Rhodopi Mountains, H. sosnowskyi has been present for more than 30 years. H. sosnowskyi poses a threat to the native biodiversity and associated ecosystem services in Bulgaria. It also poses a threat to human health as it can cause burning of the skin and blisters. As the species is included in the EU List of species of Union Concern, eradication measures should be taken against the species to prevent further negative impacts and reduce its spread.
Vladimirov V, Petrova A, Barzov Z, Gudžinskas Z (2019) The alien species of Heracleum (Apiaceae) in the Bulgarian flora revisited. Phytologia Balcanica 25, 395-405.