quincuncial

adjective

(L. quincuncialis: that holds 5/12) With a five-ranked leaf arrangement. Of the arrangement of corolla lobes in a bud, a variant of imbricate aestivation. 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 ęstivation. Quincuncial phyllotaxy: an arrangement of five leaves in a spiral, each leaf two fifths of a circle from the next.