Yes, TWINFLOWER is a Scrabble word!

Letter values in Scrabble US: T 1, W 4, I 1, N 1, F 4, L 1, O 1, W 4, E 1, R 1.

Is it a valid word?

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

creeping evergreen subshrub of the northern parts of Europe and Asia with delicate fragrant tubular bell-shaped usually pink flowers borne in pairs

Also: linnaea borealis.