Wikipedia Article About Damsons on Wikipedia This small, oval-shaped plum has an indigo skin and yellow-green flesh. Because the damson is extremely tan, it makes excellent pies and jams. The Damson is an edible drupaceous fruit, a cultivated variety of the plum tree, Prunus domestica subsp. insititia. The damson is identified by its small, oval shape (though slightly pointed at one end), smooth-textured yellow-green flesh, and skin from dark blue to indigo. The tree blossoms with small, white flowers in early April and fruit is harvested in late August, early September.