Senecio is a genus of the daisy family (Asteraceae) that includes ragworts and groundsels. The flower heads are normally rayed, completely yellow, and the heads are borne in branched clusters. Senecio is one of the largest genera of flowering plants, and despite the separation of many species into other genera it still contains over 1000 species of varied form, including leaf, stem and tuber succulents, annuals, perennials, aquatics, climbers, shrubs and small trees. Some species produce natural biocides (especially alkaloids) to deter or even kill animals that would eat them.

Senecio arenarius, commonly known as Hongerblom in Afrikaans, is a bright, hardy annual that will grow well in large parts of South Africa. This is an annual herb up to 150 to 400 mm high. The glandular-hairy leaves are more or less clasping at the base, approximately 70 mm long and lobed into broad segments. The flower heads measure 2.5 to 3 cm in diameter, resemble branched clusters or corymbs and consist of magenta ray and yellow disc florets. The cylindrical involucral bracts are free, in a single row with one to three minute bracts at the base.

This South African indigenous drought tolerant species deserves a place in all gardens that receive enough full sun to part-shade.