Numerous plant genera share the common name “toadflax.” This common name references plants with a spotted appearance that physically resemble flax, an unrelated species. The plants generally known as toadflaxes are all in the plantain family, Plantaginaeae, and can be found all over the world in a wide variety of regions. Some are cultivated ornamentally and can be obtained at nurseries and garden supply stores, while others are considered highly invasive nuisances.
Some genera commonly known as toadflaxes include Chaenorhinum, Antirrhinum, Nuttallanthus, Linaria, Anarrhinum, Cymbalaria, and Misopates. These plants are all herbaceous flowering plants with blooms in colors like yellow, red, blue, and purple, among others. It is common for toadflax to have distinctive spots on the blooms, supposedly similar to the spotted markings seen on toads in the animal kingdom.
The plants can be annual or perennial, with many being annuals. Toadflax can be seen in a variety of climates and often thrives in harsh and hostile conditions including ditches, alpine scree, and desert environments. The foliage is usually small and simple, with the plants having a plain, branching growth habit. Some are more like trailing vines and can be found climbing various objects, including other plants, in the natural environment.
Ornamental toadflax species are grown in gardens all over the world as colorful annuals. Some have been bred to produce larger, longer-lasting flowers than their wild counterparts. People can grow them from seed or purchase seedlings, and toadflax is a common inclusion in wildflower mixes. The plants will tend to naturally reseed themselves unless they are sterile, and people can collect seeds for use in the following year. Gardeners interested in exchanges can trade seeds to access new cultivars or different plants, and the seeds can also be used to prepare seed mixes as gifts for friends and family.
Invasive species are a concern in some regions where they may overrun native plants or pose a threat to animals. Some toadflax species are not safe for animals like horses, cows, and sheep to eat, and can become a problem if they appear in pastures. Others will choke out native plants because they grow quickly and reseed with ease, making it difficult for natives to compete. In regions where toadflax is invasive, eradication measures include removing plants, reseeding with native species, and using herbicides to keep plant populations down. Controlling invasive species is a special concern in vulnerable environments and ecosystems like those found on islands.