Scanning electron micrograph of a hooked fruit of cleavers or goosegrass, Galium aparine, entangled in Shetland wool. Commonly known as a bur, the fruit contains a single seed, which is dispersed by means of the barbs on the surface. The barbs attach to animal fur or human clothing & are transported for some distance before being removed. The fruit may also pass undamaged through the digestive system of some animals. The synthetic material known as velcro, used in the clothing industry as a fasterner, is based on the same principle as the hooked fruit. Mag: X160 (at 10x8 size).