NEW ALIEN PLANT SPECIES RECORDED IN THE SOUTHERN REGIONS OF LATVIA

Alien plants are one of the most dynamic and rapidly changing components of flora. Many intentionally introduced plants, which formerly were in cultivation only, now are increasingly found escaped and occur in anthropogenic or seminatural habitats. During field investigations in the southern districts of Latvia in 2014–2016, six new alien plant species were recorded: Allium nutans, Hylotelephium spectabile, Solidago ×niederederi, Symphyotrichum dumosum, S. lanceolatum and S. novae-angliae. To date, four species, Allium nutans, Hylotelephium spectabile, Symphyotrichum dumosum and S. novae-angliae, occur as casual aliens in Latvia. Solidago ×niederederi should be ascribed to the group of established species, whereas Symphyotrichum lanceolatum has naturalized and is potentially invasive. Notes on morphology and identification of species as well as characteristics of the recorded populations are discussed. A note on 20 other alien plant species recorded in wastelands, abandoned meadows and unused arable fields in the south-western part of Daugavpils city is also provided.