Mike, not 100% confident. Actual dimensions of flowerheads not recorded, but all parts (leaves, capitula, cypselas) small to very small relative to my experience with C. cunninghamii. I worked through Flora Vic (on line version ) later: a few vegetative clues (glabrescent, capitula breaking up) seemed to indicate C. minima subsp minima. I was in two minds about the importance of size, given that this plant was growing in a rock crevice: but no others evident nearby.