pentastichous
/pɛnˈtastɪkəs/Botany
adjective
Designating, relating to, or having a spiral arrangement of leaves in which there are five leaves in each turn of the spiral about the stem, and thus five vertical rows of leaves in the phyllotaxis.
Origin
Mid 19th century; earliest use found in Asa Gray (1810–1888), botanist. From scientific Latin pentastichus + -ous; compare -stichous.