Yes, CALENDULA is a Scrabble word!

Letter values in Scrabble US: C 3, A 1, L 1, E 1, N 1, D 2, U 1, L 1, A 1.

Is it a valid word?

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

any of numerous chiefly annual herbs of the genus Calendula widely cultivated for their yellow or orange flowers; often used for medicinal and culinary purposes