Yes, ENDOCARP is a Scrabble word!

Letter values in Scrabble US: E 1, N 1, D 2, O 1, C 3, A 1, R 1, P 3.

Is it a valid word?

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

the hard inner (usually woody) layer of the pericarp of some fruits (as peaches or plums or cherries or olives) that contains the seed