Answer: tapetum

AnswerCrossword Clue
TAPETUMMembranous layer
tapetumany of certain membranous layers or layered coverings, as in the choroid of the eyes of certain animals
tapetum(Latin) a reflective layer of the choroid in the eyes of many animals, causing them to shine in the dark
tapetumlayer of cells often investing the archespore in a developing sporangium and absorbed as the spores mature