Yes, CYMBIDIUMS is a Scrabble word!

Letter values in Scrabble US: C 3, Y 4, M 3, B 3, I 1, D 2, I 1, U 1, M 3, S 1.

Is it a valid word?

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

any of various plants of the genus Cymbidium having narrow leaves and a long drooping cluster of numerous showy and variously colored boat-shaped flowers; extensively hybridized and cultivated as houseplants and important florists' flowers

Not playable in Scrabble US: CYMBID.