Colletotrichum acericola sp. nov. from seeds of the invasive alien tree species Acer negundo in Poland

The boxelder maple (Acer negundo, Sapindaceae) is one of the most common tree species of the genus Acer natively growing in North America. In the 17th century, A. negundo was introduced to Europe as an ornamental plant, and from this time, it started an uncontrolled expansion into new territories, threatening local ecosystems. Fungal development on invasive alien species' seeds and pedicels was observed in 2017 and 2021 in the municipality of Wroclaw (Poland), outside of the native occurrence of the host. Morphological analyses combined with multilocus phylogenetic analyses (internal transcribed spacer [ITS], gapdh, act, tub2, chs-1 and his3 sequences) showed that isolates belonged to a new species of Colletotrichum, from the rare C. agaves species complex. The name Colletotrichum acericola is proposed for this fungus. Based on comparisons with sequences from NCBI GenBank originating from prairie plants in the United States, it is likely that C. acericola is native to North America.

Automated summary

The boxelder maple is a common tree species in North America. It was introduced to Europe as an ornamental plant in the 17th century, leading to uncontrolled expansion and threatening local ecosystems. Fungal development on the seeds and pedicels of invasive alien species was observed in Wroclaw, Poland, in 2017 and 2021. Morphological and phylogenetic analyses identified a new species of Colletotrichum, named Colletotrichum acericola, which is likely native to North America based on comparisons with GenBank sequences.