Nabalus serpentarius (commonly known as cankerweed, gall-of-the-earth, or lion's-foot) is a perennial flower species found in North America.
Nabalus serpentarius may reach a total height between , with erect stems that may vary from green to red to purple in coloration). Leaf blades are deltate to ovate in shape, reaching a length of and a width of . The margins pinnately lobed, resulting in 3 to 5 lobes.
Blooms are white to yellow in color, with petals ranging in length between . N. serpentarius blooms from August through October.
Within North America N. serpentarius can be found in the eastern United States, its native range stretching from New York to Florida and westward through Mississippi.
Nabalus serpentarius may be found in habitats such as forest ecosystems.