The Compositae are the largest and most versatile family of flowering plants. Flowers tiny, closely packed into a compound head, surrounded by sepal-like bracts. Petals are joined in a tube, and are of two kinds, with the tube ending either in five short teeth, disc florets, or in conspicuous flat flap, ray florets. Composite flowerheads are thus of three kinds: rayless, with disc florets only, like thistles; rayed with disc florets in the centres and rays florets round the edge, like daisies and dandelion-like, with all ray florets. Fruits tiny, often surmounted by a feathery pappus on which it floats away in the wind. Sometimes the pappuses form a rounded "clock".