The Collaborative International Dictionary
Hypophyllous
Hypophyllous \Hy*poph"yl*lous\, a. [Pref. hypo- + Gr. ? leaf.] (Bot.) Being or growing on the under side of a leaf, as the fruit dots of ferns.
Wiktionary
hypophyllous
a. (context botany English) Being or growing on the underside of a leaf.