Flower:

Dense, rounded flower clusters 2 to 3½ inches across at tips of one-year old branches. Flowers are creamy white, about ¼ inch across, bell to saucer-shaped with 5 rounded lobes. In the center is a single, short style and 5 long, yellow-tipped stamens that extend far beyond the mouth of the floral tube. The calyx around the base of the flower has a short tube and 5 small, triangular lobes. Flower stalks are hairless and green to red.

Leaves and stems:

Leaves are simple and opposite, lance-elliptic to nearly oval, 2 to 4 inches long, 1¼ to 2¼ inches, wide with an abrupt taper to a sharply pointed tip, and rounded at the base. The leaf stalk is ½ to 1¼ inch long, typically flattened with irregular wings. Surfaces are hairless, the upper surface dark green and shiny, lower surface paler, mostly smooth or with very tiny scale-like covering. Edges have crowded, short, sharp teeth.

Twigs are grayish brown, slender and straight, the buds pinkish-brown, slender and up to ½ inch long with flower buds appearing swollen at the base.

Older bark becomes dark gray with deeply checkered furrows, lower stems up to 5½ inches diameter. Main stems are typically multiple from base, often forming think colonies from root suckers. 

Fruit:

Fruit is a slightly flattened, elliptical, fleshy, berry-like drupe, 1/3 to ½ inch long, green turning purplish-red then darkening to blue-black, juicy, and containing a single seed.

Notes:

Nannyberry is not only common throughout most of Minnesota, it's become a fairly popular landscaping shrub in urban areas. While it's typically a densely mutliple stemmed shrub in open sites, the plant industry had deemed it fit to train it to a single stem, marketing it more as a small tree. That works only as well as the final property owner dutifully prunes out the numerous suckers it attempts to produce. Even then, it will not persist long term as a single stemmed small tree, over time losing its vigor and esthetic form.