Quincunx


A quincunx is a geometric pattern consisting of five points arranged in a cross, with four of them forming a square or rectangle and a fifth at its center. It forms the arrangement of five units in the pattern corresponding to the five-spot on six-sided dice, playing cards, and dominoes. It is represented in Unicode as or .

Historical origins of the name

The quincunx was originally a coin issued by the Roman Republic c. 211-200 BC, whose value was five twelfths of an as, the Roman standard 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 dates the first appearances of the Latin word in English as 1545 and 1574. The first citation for the 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. states that the word refers to the pattern of trees in an orchard, but then uses it more abstractly for a version of the orchard-planting problem involving patterns of points and lines in the plane.

Examples

Quincunx patterns occur in many contexts:
features a quincunx of stars.
Various literary works use or refer to the quincunx pattern for its symbolic value: