Yes, SALTWORT is a Scrabble word!

Letter values in Scrabble US: S 1, A 1, L 1, T 1, W 4, O 1, R 1, T 1.

Is it a valid word?

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

bushy plant of Old World salt marshes and sea beaches having prickly leaves; burned to produce a crude soda ash
low-growing strong-smelling coastal shrub of warm parts of the New World having unisexual flowers in conelike spikes and thick succulent leaves

Also: salsola kali, salsola soda, batis maritima.

Not playable in Scrabble US: KALI, KELPWORT.