Reservation Token
NewleafEverdell
As your action, put a Meadow or Station card face up under your Reservation token; it's not in your hand. Later play it for 1 fewer of any resource (or with another card-playing ability, not both); the token flips to its Season side until you next prepare. When you prepare for season you may discard a still-reserved card.
Also answers
reservation tokenreserve a cardreserved card