From a distance the field infested with pickerelweed (Pontederia cordata) looks attractive, but looks are deceiving. It can be difficult to eradicate if allowed to reach this level of infestation. Both pickerelweed and roundleaf mudplantain (Heteranthera reniformis) are in the same family, Pontederiaceae, which explains their resemblance. The species name, "cordata", describes the leaf shape of pickerelweed. It refers to the deeply cleft and rounded base, making the leaf heart-shaped.

The flowers of pickerelweed are quite attractive. They are arranged on a spike. In the seedling stage pickerelweed and roundleaf mudplantain are very similar.