Science Fair Project Encyclopedia
In botany, a bract is a modified or specialized leaf, from the axil of which a flower or flower stalk arises; or a bract may be any leaf associated with an inflorescence. Usually bracts are green and resemble the other leaves. However, some bracts are brightly colored and serve the function of attracting pollinators.
A small bract is called bracteole or bractlet. Technically it is any bract that arise on a pedicel instead of subtending it.
Bracts that are not solitary and appear in a whorl are collectively called an involucre. An involucre is a common feature under the inflorescence of many umbelliferous plants. Each flower in an inflorescence may have its own whorl of bracts, in this case called an involucel.
Many asteraceous plants have bracts both at the flower base and inflorescence base. Those at the flower base — chaff (recepticular bracts) — are usually minute. Those at the base of the inflorescence (a head) — the involucral bracts — are usually green, narrow and leafy.
A phyllary is one of the scale-like bracts beneath the flowerhead in Asteraceae. Together they form the involucre.
A prophyll is a leaf-like structure, such as a bracteole, subtending a single flower or pedicel. It can also mean the lower bract on a peduncle.
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details