Popping up on river banks, lake shores, and receding wetlands, the 2–4 foot tall stems are tipped with showy, dense, cylindrical spikes of small white to pinkish flowers. Note the 1–3 inch long flower clusters often droop, and the lance-shaped leaves sometimes have a red splotch near the middle. A sheath-like covering wraps around the stem at each leaf base. Also called Curlytop Knotweed and Pale Smartweed.

FLOWER: April–October. Branches erect to arching with erect to nodding, densely-packed cylindrical clusters; the tiny, white to pinkish flowers are 1/8 inch long (3 mm) with 4 (sometimes  5) petal-like tepals that barely open.

LEAVES: Alternate. Blades linear to lance-shaped, 2–8 inches long (5–20 cm) by 3/16–1 1/2 inches wide (5–40 mm), tapering to a sharp tip; prominent mid-vein on upper side, sometimes with red splotch; margins entire; a sheath-like covering with a smooth upper edge (without bristles) wraps around the stem at the base of each leaf.

HABITAT: Moist to wet, sandy, silty soils; ditches, floodplains, sandbars, marshes, shorelines, moist places.

ELEVATION: 3,000–9,370 feet.

RANGE: Widespread in North America; occurs in every state, and on every continent except Antarctica.

SIMILAR SPECIES: Pennsylvania Smartweed, Persicaria pensylvanica, in much the same range and habitat, shares many of the same features, but always has erect clusters of white to pink flowers with 5 tepals. The widespread rhizomatous perennial Water Smartweed, P. amphibia, can reach 4 feet tall in damp soil, or can grow in shallow water with its erect, reddish flower spike above water and floating leaves with long stalks (petioles). The widespread, non-native Spotted Lady’s Thumb, P. maculosa, has leaf-sheaths with bristly upper edges, and usually has dark splotches on the leaves.

NM COUNTIES: Nearly statewide throughout NM, from low- to high-elevation, moist habitats; not reported in De Baca, Luna, Torrance, Quay counties.