Findings and expansion of rare adventive species of plants in the Altai Territory

This paper contains previously unknown information about the appearance and expansion of a number of adventive species of plants new for the Altai Territory. They were discovered in 2008–2012 during the fieldwork tasks of the herbarium Altai State University, Barnaul. One of the species is invasive (quarantine plant for the Russian Federation) – Acroptilon repens (L.) DC. The range was about 10 ha. One of the species was listed as adventive for the first time – Briza maxima L. The species is sometimes cultivated as an ornamental plant. New locations were identified for three species previously found only in one area of the Altai Territory: (1) Scleranthus annuus L. – an agrophyte, a weed that spreads with cultivated crops; (2) Onopordon acanthium L. – a species that spreads in flood plains, along the highways, railways and pastures; and (3) Xanthium albinum (Widd.) H. Schulz – a plant, often seen along roadsides, wastelands and sandy riverbanks; only one reliable location within the Altai Territory was kn...