I've loved this little wildflower, ivy-leaved toadflax (Cymbalaria muralis), for many years. I feel like it's following me around. This enchanting trailing wildflower was first introduced into UK gardens in the 17th century, and along its journey it has colonised not only the exterior of old garden walls, but found its way into the lower wall areas of old glasshouses; and yet, can also be described as an escapee of glasshouses!
This delicate but incredible wildflower is a member of the Plantaginaceae family, native to the rocky habitats of Southern Europe and since naturalised in many temperate locations, including the UK. It's not classified as a top-tier invasive species.