Depending on one’s perspective, birdsfoot lotus (Lotus corniculatus) can be considered a wildflower, a valuable forage for domestic livestock and wildlife, a garden ornamental, a nectar and food source for insects, useful for erosion control – or a noxious, invasive weed. A non-native perennial introduced from temperate Eurasia and Northern Africa in the early 1900s, birdsfoot lotus has become naturalized throughout most of North America.
Found in grassy places and waste areas, birdsfoot lotus is a prostrate, sprawling plant arising from a branching tap root with side roots near the soil surface. The slender, well-branched stems, up to 1 1/2 or 2 feet in length, grow in a tangle. The compound, alternate leaves have no stalks and consist of five leaflets. The three central leaflets are conspicuously above the other two leaflets. The two lower leaflets resemble stipules. Because birdsfoot lotus leaves look as though they have three leaflets and two stipules, this plant is often commonly, yet incorrectly, called a trefoil (three leafed). In darkness birdsfoot lotus leaves close around the stem.
Birsdfoot lotus has five-petaled, bright yellow flowers typical of Pea Family members. The flowers occur in whorls at the ends of the stems. The flowers may be tinged with red and often turn orange as they age. The name “birdsfoot” derives from the arrangement of the brown, inch long seedpods on the stem.
Also called birdsfoot deervetch, this legume (or at least the bacteria on its roots) fixes nitrogen in the soil. Cultivated with other grasses, birdsfoot lotus is used as pasture for livestock or harvested as hay and silage. Because birdsfoot lotus contains tannins it is less desirable for horses. However, since birdfoot lotus does not cause bloat (probably because of those very tannins), it is good feed for cattle and sheep. Wildlife such as deer, elk and geese also forage on birdsfoot lotus. Insects seek out birdsfoot lotus nectar and the plant is larval food for several species of butterflies.
Birdsfoot lotus forms dense mats and is therefore useful for erosion control along roadbeds and hillsides. Yet this trait of forming thick tangles chokes out and shades other plants displacing desirable vegetation, at which point birdsfoot lotus becomes a noxious weed.
Some references to birdsfoot lotus as a medicinal herb occur in the literature. Because birdsfoot lotus contains hydrogen cyanide, which may be poisonous in large amounts, care must be taken if ingesting birdsfoot lotus. Once dried the plant is not longer poisonous. An orange-yellow natural dye can also be made from the flowers.
These plants were growing in the McArthur Swamp near the Tule River (Shasta County CA).
Birdsfoot lotus has not invaded our pastures, we do not use it to feed our livestock nor do I have medicinal or other uses for this brilliant yellow flower. To me birdsfoot lotus is a pretty “wildflower” whose colorful blossoms look cheerful peeking out amid the surrounding vegetation.