The Marian Plum is a cousin of the mango in miniature. Marian Plums ripen in March to May. It has an oval shape, with green skin, and ripen to a bright yellow or orange skin. Marian Plum has two species: sweet and sour. Sweet Marian Plum is eaten when ripe, while sour Marian plum is used for making chili dip or eaten with a sweet and salty sauce.