Dotted smartweed is an annual or perennial native herb. It grows to 0.5 m tall in moist ground, shallow water and marshes. It's often found in more shady areas than other smartweeds. The leaves have a
very sharp peppery taste, often somewhat delayed.
Origin of the name: Polygonum: Gr. polys, many; Gr. gony, knee; refers to the swollen nodes or "many joints"
As in all smartweeds, the nodes on the stem are swollen and each leaf forms a sheath around the stem called an "ochrea." The ochrea extends up
the stem from the node where the leaf is attached. Most smartweeds require mature fruit to identify the species.
Leaves are alternate and lance-shaped up to 20 cm long with smooth margins. The
stems and leaves are smooth.
Small white flowers bloom through August and September. The inflorescence is an erect raceme but the flowers have irregular spaces between them. The base of each
flower has yellow glandular dots visible with a lens.
Dotted Smartweed is similar to False Water Pepper (P. hydropiperoides) which lacks the pepper taste, and to Water Pepper (P. hydropiper) which is peppery,
but whose racemes are continuous rather than interrupted, and has greenish flowers.
punctatum: L., punctum, a point; refers to the dotted tepals
Range: Que. to BC, s. to S. Amer.
WI Range: Statewide
Common associates: Rice cut grass, bluejoint grass, arrowhead
Wetland Indicator Status: OBL
Coefficient of Conservatism: C = 6 (S&W) C = 5 (MI)