Definition of "foliar"

Warming (1870) (69) is confident that it is not an independent foliar appendage, for ontogenetic proof, analogy to other genera, and the course of vascular strands indicate that it is a foliar organ which is closely allied to the involucre.

1924, Julia Moesel Haber, The Anatomy and the Morphology of the Flower of Euphorbia, page 116