Quin*cun"cial (?), [L. quincuncialis, from quincunx. See Quincunx.]
1.
Having the form of a quincunx.
2. Bot.
Having the leaves of a pentamerous calyx or corolla so imbricated that two are exterior, two are interior, and the other has one edge exterior and one interior; as, quincuncial aestivation.
Quincuncial phyllotaxy Bot., an arrangement of five leaves in a spiral, each leaf two fifths of a circle from the next.
© Webster 1913.