Yes, OREGANO is a Scrabble word!

Letter values in Scrabble US: O 1, R 1, E 1, G 2, A 1, N 1, O 1.

Is it a valid word?

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

aromatic Eurasian perennial
pungent leaves used as seasoning with meats and fowl and in stews and soups and omelets

Also: pot marjoram, wild marjoram, winter sweet, origanum vulgare.