Flower:

Branching cluster, usually crowded and compact at the top of the stem, plus densely packed, long-stalked, spike-like racemes to 3 inches long arising from the upper leaf axils. Flowers are about ¼ inch across, somewhat bell-shaped with 5 spreading tepals (petals and similar sepals) that are white, often greenish at the base. In the center is a 3-parted style surrounded by a ring of yellow glands and 8 stamens with white or pink tips. Cluster stalks are hairless or hairy in lines.

Leaves and stems:

Leaves are alternate, 1 to 3 inches long and about as wide, triangular to arrowhead-shaped, tapered to a pointed tip (often abruptly so), straight across to slightly heart-shaped to angularly lobed at the base, toothless, and hairless except for a fringe of fine hairs around the edges. Lower leaves are long stalked, becoming shorter stalked as they ascend the stem. Leaves are often wavy around the edge.

At the base of the leaf stalk is a green to reddish, membranous sheath (ocrea) with pale ribbing, its upper edge smooth to jagged, the base finely short-hairy. Stems are erect, green or red, smooth to ridged, unbranched or branching in the upper plant, mostly hairless except for fine lines of hairs on the upper stem and at the leaf nodes.

Fruit:

Fruit is a dry seed (achene), up to ¼ inch long, much longer than the tepals, strongly 3-sided, minutely winged along the angles, smooth across the surface, light brown at maturity sometimes with darker streaks.

Notes:

Buckwheat, related to Docks and Smartweeds, is one of the showier members of the Polygonaceae family. Originating in Asia, it was introduced to the rest of the world as a cereal crop and is now often used as a cover crop. It escapes cultivation but does not typically persist in the wild for long. It is one of the easier Polygonaceae species to ID from the upright habit, triangular to arrowhead-shaped leaves, racemes of ¼-inch white flowers arising from upper leaf axils and usually a branching cluster at the top of the stem.