Question 4

Is it invasive in the wild?

Pioneers in our early melting pot days intentionally brought along plants with long histories of use as herbal medicines, seasonings, or foods. Immigrants brought their beloved Chicory to provide future edibles and an alternate source of coffee, and Common toadflax as an ornamental to festoon the gardens of homesteaders. Seeds traveled here accidentally: in pants’ cuffs, or in the ballast of ships, or mixed with other crop seeds or packing materials.

They also inadvertently brought invasive weed populations with them, since these imports escaped into the wild. Settlers did not import the old eco-systems that kept weeds, their predators (bio-controls) and the nemeses of their predators (critters to eat bio-controls) in balance. As they traveled, they were preoccupied about basic survival on their voyage into an uncertain new world. Adventurers were not worried about the future of these plants and their environmental impact centuries hence. The future has arrived, the early uses for many of the plants have faded away, yet the legacy of the weeds continues.

Prairie invaders

Common toadflax, Linaria vulgaris, a.k.a. Butter-and-eggs, arrived with the new colonists. It was oh-so-easy to grow, since it thrives in airless, infertile soils with low calcium and humus. The new adventurers had enough of a struggle with the perils of the new environment, and welcomed its simple cheer in the yards of their new homesteads. It headed west with the miners and their families and was not a problem for its first century here. Now, however, it has become a noxious weed in 9 states and endangers stretches of pasturelands in Colorado. While those who sought to find gold have since disappeared, the gold in its yellow blooms lingers on.

Left: Yellow toadflax flowers and seeds simultaneously… Right: with luscious nectar spurs and blooms

It feeds and shelters bees and other pollinating insects. Its flowers bloom beautifully over a long season and exceed the size of its foliage, so both wildflower and weed books include it as one or the other. But beware…