Yes, SASSAFRAS is a Scrabble word!

Letter values in Scrabble US: S 1, A 1, S 1, S 1, A 1, F 4, R 1, A 1, S 1.

Is it a valid word?

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

yellowwood tree with brittle wood and aromatic leaves and bark; source of sassafras oil; widely distributed in eastern North America
dried root bark of the sassafras tree

Also: sassafras tree, sassafras albidum.