1) A small modified leaf, or scale, growing immediately below the calyx of a plant, or upon the peduncle of a flower. 2) In botany, a modified leaf (also known as a phyllary) that accompanies a flower or an inflorescence. It can have a different shape, colour and consistency according to its protective, banner, nectar-secreting or spreading function.
Source: 1) Encyclopaedia Britannica 2002 2) De Agostini - Sapere.it