Dog fennel has a taproot and does not root at nodes. Perhaps the plant's most distinctive feature is the large flower with white petals and a yellow center. Ground ivy is a low-growing, creeping, perennial broadleaf weed. Leaves are oppositely arranged on stems and are round or kidney-shaped with scalloped margins. The upper leaf surface has distinct veins and is sparsely hairy.
Stems are square, creeping, and long.
Ground ivy produces nodes that root at leaf and stem axils and that can form new stolons. Flowers are blue or purple and trumpet-shaped. This weed is most common in shaded areas, but it can also grow in full sun. As with other members of the mint family, stems are square. Flowers are violet to purple and are produced in dense clusters at the tips of branches.