/pi ras"ti kee/ , n. , pl. parastichies . Bot.
one of a number of seemingly secondary spirals or oblique ranks winding around the stem or axis to the right and left in a spiral arrangement of leaves, scales, etc., where the internodes are short and the members closely crowded, as in the houseleek and the pine cone.
[ 1870-75; PARA- 1 + STICH 1 + -Y 3 ]