Wild Plum
Prunus americana

Family: Rose (Rosaceae)
AKA: American Plum
Photo taken on: April 26, 2014
Location: Abiquiu, NM
Life Zones: Plains and foothills
Habitat: Moist areas, ditches, canyons

A small tree or shrub growing to 15ft tall in thickets with thorny branches. Leaves are finely toothed. The upper surface of the leaves is dark green, the underside is pale. Flowers bloom before the leaves and have five petals. Round fruits are 1" across and can be yellow or red and are edible.  

Flora of North America reference.