From April to May, tourists as well as researchers can appreciate the invasive California poppy (Eschscholzia californica) coloring of bright orange the roadsides and mountain slopes on the ascent to mount Teide in Tenerife, Canary Islands. The species was introduced as an ornamental plant and reports of its occurrence as a widespread ruderal species only date back to the 60’s. Since then, it has expanded into the natural vegetation quite rapidly. Its ability to tolerate high temperatures, drought, variable precipitation regimes, and a wide range of soil textures, chemistries, and levels of fertility can help us understand its success in new regions (such as Chile, Australia, and several European countries) far away from its original range in the Western United States.
In Tenerife, this charismatic poppy does well in the cloud layer habitats where the pine forest thrives, but it was also once found as far up as the subalpine zone, in the Teide National Park. Thanks to the eradication efforts of the group of biological invasions of the Canary islands (IBIOCA), it is no longer found there. While still being part of the weed control program along the roadsides surrounding the national park (in the Corona Forestal Nature Park), it is also promoted as a touristic attraction by travel agencies. The species definitely challenge our perceptions and definitions of weeds and noxious species!
The most complete compilation of information on the California poppy can be found here: https://plants.usda.gov/plantguide/pdf/pg_esca2.pdf.