Bracts

Bracts are modified or specialized leaves associated with a reproductive structure in flowering plants. They occur on various parts of the plant, most commonly subtending individual flowers, surrounding an inflorescence, or forming conspicuous structures that resemble petals. Bracts may be green and leaf-like, or brightly colored to attract pollinators or protect the floral organs within.

Bracts are different from petals: petals are floral organs forming part of the perianth, whereas bracts derive from ordinary leaf tissue and may be sterile or, less commonly, partially fertile. When bracts are colored or enlarged they can enhance visibility of the flowers, as in some ornamental species; when they are protective, they shield developing florets from desiccation or damage.

Common examples include: the brightly colored bracts around the small flowers of Bougainvillea; the large spathes surrounding the flowers of peace lilies (Spathiphyllum) and other arums (Araceae); the red bracts of poinsettias (Euphorbia pulcherrima) which are modified leaves rather than petals; and the involucral or surrounding bracts of many Asteraceae heads. In grasses and related families, the term bract is used for the glumes that enclose the florets at the base of a spikelet.

The study of bracts encompasses morphology, development, and function in pollinator ecology, and they are a common feature in horticulture and plant identification.