Yes, LAMELLAE is a Scrabble word!

Letter values in Scrabble US: L 1, A 1, M 3, E 1, L 1, L 1, A 1, E 1.

Is it a valid word?

LAMELLAE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any of the radiating leaflike spore-producing structures on the underside of the cap of a mushroom or similar fungus
a thin membrane that is one of the calcified layers that form bones
thin plate