Bract

Bract, a leaf in, or immediately below, an inflorescence, having in its axil either a flower-bud or a branch bearing flower-buds. The main function of the bract is to protect the young buds. It may be leafy, differing in no respect, save position, from an ordinary foliage-leaf, as in the dead-nettles; or it may be rigid or gluinaceous, as the so-called "chaff" in grasses and sedges; or it may be thinner, brown or colourless and membranous, as in Pelargonium; or it may be conspicuously coloured, so as to serve an attractive purpose such as is usually the function of the corolla, as in Poinsettia or Bougainvillea (q.v.). If a bract is large and encloses a whole inflorescence it is termed a spathe, and spathes may similarly be leafy as in Arum maculatum, membranous as in palms, or coloured and fleshy as in Anthurium or Richardia. A circle or larger collection of bracts below an inflorescence is termed an involucre, as in the case of the three leafy bracts on the flower-stalk of Anemone nemorosa, the two circles of bracts, the outer recurved, in the dandelion, the fleshy-based bracts of the artichoke, the coloured circle of bracts of Astrantia, etc. The flower in the axil of a bract, if belonging to a dicotyledon, has often two smaller bracts or bracteoles placed laterally on its pedicel, as may be seen in violets. If a monocotyledon, there is only one bracteole on the pedicel on the side nearest the bract. The scales in the catkins of some trees and the husk that remains under the name of cupule round the fruit of others, as, for example, the "cup" of the acorn, are variously made up of confluent bracts and bracteoles, and the minute scales or paleae among the florets on the common receptacle of some Compositae may be looked upon as bracteoles.