It seems that those of us who live in Mediterranean climate zones (mainly central and southern California, Chile, western Australia, South Africa, and, of course, the lands bordering the Mediterranean Sea) are prone to infestation by plants that seek refuge on our clement shores. Thus fennel has infiltrated the area around Santa Barbara and pampas grass forms an inflammable mass wherever it can gain a foothold.
SAF appeared here several years ago, probably planted by a bird who'd eaten its attractive red berries. I knew I'd seen it as a filler in flower arrangements and as a beloved potted plant in the midwest, so assumed it was a gift from the beneficent Mother Nature. Lovingly transplanted to an area of poor soil where nothing much would grow, SAF was reliably green and very soft-looking, though prickly enough to draw blood whenever I took time to cut it back.
My SAF bed used to be part of a driveway, so had lost its topsoil sometime during the early 1950s. When we moved here in 1975, this part of the yard was kneedeep in Algerian ivy, which I laboriously exterminated. Focusing on the bulbs, succulents, and specimen plants (camillia, azalea, lavender, etc) I had planted in other parts of the yard, I left the SAF as a sort of backdrop until this year.
Now that I have embarked on an overall garden improvement spurred on by our acquisition of rainbarrels and Ramona's talk of permaculture, I shall feed the depleted soil before replacing SAF with less invasive plants.
The invasive species issue is of much greater concern than what I will be calling botanical imperialism, the naming of African, Asian, and New World native plants after the European botanists who "discovered" them. But you can be sure I'll return to the Sprengers, Meyers, and Frieses who caught Linnaeus' attention in the late 18th century.