Chaff

From Wikipedia, the free encyclopedia

For the radar countermeasure, see Chaff (radar countermeasure).

For the SAT algorithm, see Chaff algorithm.

Rice chaff

Chaff is an agricultural term used for the bracts and casings of cereal grain that are harvested along with the grain. These casings include hulls or husks and part of the pericarp. In botany the bracts are called glumes. The bracts and husks are harvested with cereal grains such as rice and wheat and separated from the grain, by such techniques as threshing and wind winnowing. The chaff is a byproduct of grain production and is often used for animal feed, while the grain is often made into flour.

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. In grasses (Poaceae), the bracts that enclose the florets are termed glumes. They are sterile bracts found below the flowers in a spikelet, the basic unit of a grass inflorescence. Spikelets typically have two basal glumes, with one or more florets above. However, one or, more rarely, both glumes may be lacking in some taxa.^[1]

1 Other meanings
2 See also
3 Sources
4 Further reading

[edit] Other meanings

Agriculture

Hay or straw cut into very short lengths is also called chaff (it serves the same agricultural purposes). The cutting is often done by a specially designed machine called a chaff cutter and fed to horses or cattle.

Botany

In botany, "chaff" refers to the receptacular bracts of many species in the sun flower family Asteraceae. They are modified leaves that are scale like and surround flowers. Note the inside of a sun flower inflorescence. They are often called chaffy bracts, which act as spacers between the flowers

Metaphor

"Chaff" is also used to refer to something worthless, such as in the expression "separating the wheat from the chaff", meaning to find things of value and separate them from things of no value. For example Psalm 1 of the Bible says: "Not so the wicked! They are like chaff that the wind blows away".