All flowers in a head share a common receptacle. The receptacle may be flat or convex. It may bear tiny scales called paleae. The paleae of a receptacle are referred to as chaff. Receptacles without paleae are said to be epaleate or naked. When the paleae are shed, they may leave either a smooth or a pitted receptacle. Occasionally, hairs, scales, or bristles may also be present on the receptacle.