Flower:

Erect, spindly, unbranched racemes to 3 inches long in leaf axils along most of the stem. Flowers are 1/8 inch long, greenish white, sometimes tinged purplish, with usually 5 tepals (petals and similar sepals) that are generally oval and barely spreading. 8 stamens surround a green column in the center. Flower stalks are slender and hairless or with a few rough scales on the upper end.

Leaves and stems:

Leaves are simple and alternate, ½ to 3 inches long and up to 2 inches wide, heart to arrowhead shaped, the basal lobes often sharply angled, and tapering to a sharply pointed tip. Leaf edges are toothless but somewhat wavy. Surfaces are minimally rough textured from short, hair-like projections (scabrid) along the lower veins, leaf edges, and in rows on the slender stalk. A small sheath at the base of the leaf stalk, called an ocreae, is shed as the leaves become mature. Stems are twining across the ground or on surrounding vegetation, often becoming reddish with age in dry sunny locations and have rows of short, rough hairs.

Fruit:

Fruit is 3-sided, less than ¼ inch long. Inside the husk is a seed covered with minute, granular projections (tuburcles); the seed ripens to dull black.

Notes:

Black-bindweed is one of three common vining species in the Fallopia genus in Minnesota and the only non-native of the three. It can be distinguished from the native Fringed Black-bindweed (Fallopia cilinodis), which has darker green leaves with pronounced veins, a ring of fine cilia hairs at the base of the leaf stalk, and denser, branched clusters of conspicuously open, white flowers. The other native, Climbing False Buckwheat (Fallopia scandens), is similar to Black-bindweed as it lacks the cilia fringe at the leaf nodes and its flower clusters are also generally unbranched, but its small obscure flowers develop quickly into large hanging fruits with prominent wings on the three outer tepals and its mature seeds are smooth, shiny black, where Black-bindweed fruits are wingless and mature seeds are dull black and textured.