The Collaborative International Dictionary
Phelloderm
Phelloderm \Phel"lo*derm\, n. [Gr. ? cork + -derm.] (Bot.) A layer of green parenchimatous cells formed on the inner side of the phellogen.
Wiktionary
phelloderm
n. (context botany English) The innermost parenchymatous tissue of the periderm of some plants