The flowerheads of Senecio muirii grow in few-flowered, branched panicles on fleshy stalks. Each flowerhead comprises a dense cluster of disc florets, enveloped by one row of oblong bracts, green to purple in colour and cohering to form a cylindrical base for the flowers. Thin, leafy bracts are visible in the photo, both at the base of the stalks and the flowerheads.

The tiny florets have creamy white, recurving segments, the yellow of the well exserted anthers and stigmas conspicuous. Flowering happens in early autumn (Smith and Crouch, 2009).