Flower:

 Numerous rounded clusters from buds at the tips of branches, each cluster a 1 to 4-flowered umbel (stalks all arising from the same point) and emerging before the leaves in spring. Flowers are 1 to 1¼ inch across with 5 white to pale pink, round to egg-shaped petals with a single slender style and a spray of slender, white to pink, yellow-tipped stamens in the center.

The 5 sepals are typically red, lance-oblong, about 1/3 the length of the petals, spreading, the tip blunt with glands or glandular teeth along the edges. The inner surface is smooth and the outer smooth or occasionally hairy. Flower stalks are slender and hairless.

Leaves and bark:

Leaves are simple and alternate, 2½ to 4¼ inches long and 1½ to 2¾ inches wide, the blade broadly oval-elliptic to lance-oblong, often widest above the middle, abruptly tapered to a point, tapered or rounded towards the base, on a 1/3 to 2/3 inch, hairy stalk with a few small glands near the leaf blade. Edges are finely double toothed with blunt teeth and a small gland at the tip of each tooth. Upper surface is dark green, sparsely hairy, the lower surface is lighter and sparsely to densely hairy, especially along the veins.

Twigs are reddish brown to gray, smooth or occasionally sparsely hairy. Branches are spreading to ascending with older lateral twigs developing into stout spines that are up to 2 inches long and occasionally compound.

The trunk can be up to 2¾ inch diameter at breast height, the bark is initially gray and smooth becoming coarse and peeling with age.

Fruit:

Fruit is a purplish red drupe with a thin waxy bloom, about 1 inch in diameter and a single hard seed inside.

Notes:

Canada Plum is similar to American Plum (Prunus americana), though it is more of a forest species and their ranges over lap where the forest meets the prairie. In comparison, Canada Plum has proportionately broader leaves with blunt, gland-tipped teeth and glands on the leaf stalk, where American Plum has sharply toothed leaves and only a few glands on the blade edge near the stalk. Canada Plum is also more open with ascending branches and while it does sucker, forming colonies, they are not typically as dense as American Plum.