Virginia Buttonweed, Diodia virginiana, is a native plant that could cause problems in both your yard and pasture. This warm season perennial is a prostrate plant with spreading branches. These branches can form roots at each node, causing it to spread like a mat. Mainly a problem in the southern US, buttonweed is found along the Ohio River Valley in Ohio, at its northern extent.
The buttonweed plant has opposite leaves 1-3 inches in length and less than an inch wide. As the plant matures, older leaves will begin turning purple. Leaves are also known to become yellow-mottled due to a virus that attacks the plant. Small white star shaped flowers with four petals, bloom beginning in the summer through the fall. Sometime the flower will have purple streaks. This plant grows in disturbed areas and areas with moist soils. Having a healthy pasture helps prevent weeds from being introduced. Having a thick grass layer that is not overgrazed is key. Overgrazing causes openings to the soil where weeds can then occupy. Proper soil chemistry is also key, take those soil samples and follow the recommendations. Pastures need proper nutrition to grow healthy. Improving the drainage of your fields, sometimes difficult in our county, will keep this weed at bay. If this plant is a nuisance in your pastures, follow state extension fact sheets for best methods of control.