Yes, CHLAMYDES is a Scrabble word!

Letter values in Scrabble US: C 3, H 4, L 1, A 1, M 3, Y 4, D 2, E 1, S 1.

Is it a valid word?

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

collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils
a short mantle or cape fastened at the shoulder; worn by men in ancient Greece

Also: floral envelope.

Not playable in Scrabble US: PERIGONE, PERIGONIUM.