Gardeners use this term to identify any accidental variation from normal in the flower, habit of growth and so on of a plant. It does not cover variations arising whenis sown. , carnations and roses are especially liable to ‘sporting’; e.g. if a red flower appears on a shoot of a yellow variety of rose, it is termed a sport, as is an unexpected climbing shoot on a bush variety. To perpetuate such sports, buds, etc., must be taken from the particular shoot and not from elsewhere on the plant. Once plants of the sport are established, buds, cuttings, layers and so on, may be taken in the usual way. Sporting is caused by an alteration in the character of one or more genes (the units of inheritance) contained in the chromosomes.