About Kummerowia stipulacea (Maxim.) Makino
Kummerowia stipulacea (Maxim.) Makino is a species of flowering plant in the legume family, commonly known as Korean clover. It is native to China, Japan, Korea, and Russia, and is an introduced species in the eastern United States. This annual herb produces prostrate, spreading, or erect stems, and grows up to 60 centimeters tall. Its leaves are composed of three oval leaflets. Between one and five flowers grow from the leaf axils. This species produces two types of flower: cleistogamous flowers, which self-fertilize and never open, and chasmogamous flowers, which open and receive pollen from other plants. Chasmogamous flowers are purple-blue in color. The fruit is a small legume pod that holds one seed. Kummerowia stipulacea often grows alongside its congener Kummerowia striata, but can be easily identified by its large papery stipules, which are especially visible on young leaves. The species was first introduced to the United States intentionally in 1919, when it was planted in Arlington, Virginia by the USDA. Kummerowia stipulacea and Japanese clover were used to revegetate abandoned coal mine sites. Its seed was spread to attract wildlife, and it was grown as forage for livestock. It was also planted to prevent erosion along roadsides, and rotated with cereal crops to improve soil quality. After introduction, the species persisted and spread. Today, it grows wild, provides food for many mammal and bird species, remains a high-quality livestock forage, and its seed is still sold for planting. Three cultivars are available: "Climax", "Harbin", and "Rowan". While it is classified as a weed in some areas, it is not very aggressive and is not considered a noxious weed.
