(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