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 glastifolius, commonly known as Large Senecio in English and Waterdissel in Afrikaans is an upright perennial growing about 1 m tall with a woody base and glossy green foliage along the branched stems. The cheerful flowers, that attracts bees, are large daisies, a single row of mauve petals around a yellow centre, formed at the tips of the stems. These appear from spring to early summer. The plants enjoy full sun and performs at its best with regular watering. The edges of the lanceolate (lance-shaped) leaves are coarsely toothed and can be quite prickly. These leaves are so distinct that even the young seedlings are easy to recognize in the veld. The young plants respond very well to organic fertilizer. Its height makes it perfect to use at the back and in the middle of beds, combined with smaller Namaqualand daisies in the front.