Yes, ENDIVE is a Scrabble word!

Letter values in Scrabble US: E 1, N 1, D 2, I 1, V 4, E 1.

Is it a valid word?

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

widely cultivated herb with leaves valued as salad green; either curly serrated leaves or broad flat ones that are usually blanched
variety of endive having leaves with irregular frilled edges

Also: cichorium endivia, chicory escarole.