Your search for "plains 337" revealed the following:
Plains (337) (C16) from Commander 2016, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Rebecca Guay
Plains (337) (C13) from Commander 2013, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: John Avon
Plains (318) (C14) from Commander 2014, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: John Avon
Plains (031) (Foil) (SLP) from Secret Lair Promo, available at 401 Games Canada. Rarity: Rare Finish: Foil Artist: John Avon