Yes, SYRINGA is a Scrabble word!

Letter values in Scrabble US: S 1, Y 4, R 1, I 1, N 1, G 2, A 1.

Is it a valid word?

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

large hardy shrub with showy and strongly fragrant creamy-white flowers in short terminal racemes
genus of Old World shrubs or low trees having fragrant flowers in showy panicles: lilacs

Also: mock orange, philadelphus coronarius, genus syringa.