Senecio maritimus stem-tips branch when flowering, producing spaced heads of yellow flowers, mainly in spring. About eight rays spread and curve back around the stacked, yellow disc florets over the green, cup-shaped involucre of every head.

The leaves vary in shape, the toothing also variable (Manning, 2007; Manning and Goldblatt, 1996; Bond and Goldblatt, 1984; iNaturalist).