Introduced species. Still not as widespread in Portugal as Phytolacca americana, an invasive species, but certainly going that way.
The Yellow Flag has created a band of vegetation around the Northstar Park pond (Davis, CA) about 3 feet wide. It has been there for several years.
4 immature swans preening, and a Canada Goose in the background. The two parent swans were nearby but I didn't get them in a photo. They have a nest at the other end of the lake.
Seeking to document observations of non-native introduced species outside of their original homelands. Observations must be of organisms that were introduced to an area by humans recently (established populations of introduced species are okay), not natural shifts in range, or migrations.