Didelta spinosa, the great salad thistle or in Afrikaans the perdeblom (horse flower), is a shrub to 2 m with solitary yellow daisy flowerheads. A single array of narrowly elliptic ray florets surrounds the yellow disc. A small patch of still unopened disc florets can be seen in the centre of the disc on the specimen in picture. Some withered disc florets on the outside of the disc right next to the rays and a ring of currently flowering, unkempt pale yellow disc florets inside them, indicate how the flowering begins on the outside and gradually reaches the florets closer to the centre. On each ray floret two longitudinal grooves can be seen, as well as notched tips on some of them.
The leaves are shiny green, oval to elliptic with margins slightly rolled under. Tiny white spines are found at the leaf tips on the plant in the photo. The spines are apparently not always present. The plant is distributed along a strip on the west coast from Saldanha to the Gariep and into Namibia. It grows on dry, rocky slopes. Flowering happens from midwinter to early spring.
This photo was taken near Springbok early in September (Manning, 2009).