oxeye daisy, (Leucanthemum vulgare), perennial plant in the aster family (Asteraceae), commonly grown as an ornamental. The oxeye daisy is native to Europe and Asia and has naturalized in the United States. The plant grows about 60 cm (2 feet) high and has notched oblong leaves and long petioles (leafstalks). The attractive compound flower heads have 15–30 white ray flowers surrounding numerous yellow disk flowers and are about 2.5–5 cm (1–2 inches) across. See also daisy.