Kickxia elatine is a species of flowering plant in the Plantaginaceae known by several common names, including sharpleaf cancerwort and sharp-leaved fluellin. It is native to Europe and Asia, but it is present on other continents as an introduced species, and sometimes a noxious weed. This is a small hairy herb with a trailing stem with many branches. It produces oval to arrowhead-shaped fuzzy leaves at wide intervals along the slender stem, and solitary snapdragon-like flowers borne on long, straight pedicels. Each flower is up to 1.5 centimeters long with a narrow, pointed spur extending from the back. The lobes of the mouth are yellow, white, and purple, and the whole flower is fuzzy to hairy. The fruit is a spherical capsule about 4 millimeters long.