Editing Quincunx (section)

==Historical origins of the name==
[[File:Vecchi 281.jpg|thumb|left|150px|A [[Quincunx (Roman coin)|quincunx coin]]]]
[[File:Portuguese shield.svg|thumb|150px|[[Coat of arms of Portugal|Portuguese shield]]]]
The [[Quincunx (coin)|quincunx]] was originally a coin issued by the Roman Republic {{circa|211&ndash;200 BC}}, whose value was five twelfths (''quinque'' and ''uncia'') of an [[as (coin)|as]], the Roman standard [[aes grave|bronze]] coin. On the Roman quincunx coins, the value was sometimes indicated by a pattern of five dots or pellets. However, these dots were not always arranged in a quincunx pattern.

The [[Oxford English Dictionary|''Oxford English Dictionary'' (OED)]] dates the first appearances of the Latin word in English as 1545  and 1574 ("in the sense 'five-twelfths of a pound or as{{'"}}; i.e. 100 old pence). The first citation for a geometric meaning, as "a pattern used for planting trees", dates from 1606. The OED also cites a 1647 reference to the German astronomer [[Kepler]] for an astronomical/astrological meaning, an angle of 5/12 of a whole circle. When used to describe a tree-planting pattern, the same word can also refer to groups of more than five trees, arranged in a [[square grid]] but aligned diagonally to the dimensions of the surrounding plot of land; however, this article considers only five-point patterns and not their extension to larger square grids.

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