pen·tas·ti·chous \(ˈ)pen.|tastə̇kəs\adjective Etymology: New Latin pentastichus, from penta- (from Greek) + -stichus -stichous : arranged in five orthostichies in such a manner that each leaf diverges from the preceding by an angle equal to two fifths of the circumference of the stem so that the sixth leaf stands above the first < pentastichous arrangement of leaves > • pen·tas·ti·chy\ ̷ ̷ˈ ̷ ̷ ̷ ̷kē\noun-es