If this card is sent to the Graveyard to pay a cost, used as a Tribute (either as a cost or for a Tribute Summon), or as a Synchro Material Monster, you cannot activate its effect.
Well how is this supposed to be understood just by its vague effect description?
If it was something along the lines of:
When this card is sent from the field to the Graveyard as a result of Battle or Card Effect, you can select 1 “Naturia” monster in your Graveyard, except “Naturia Eggplant”, and add it to your hand.