Water Smartweed, Water Knotweed: Persicaria amphibia (Synonyms: Polygonum amphibium, Polygonum amphibium var. coccineum, Polygonum amphibium var. emersum, Polygonum amphibium var. natans, Polygonum amphibium var. stipulaceum, Polygonum coccineum, Polygonum coccineum var. coccineum, Polygonum coccineum var. hartwrightii, Polygonum natans, Polygonum natans var. hartwrightii) -
Marshpepper Smartweed, Mild Water-pepper, Smartweed: Persicaria hydropiper (Synonyms: Polygonum hydropiper, Polygonum hydropiper var. projectum) -
Swamp Smartweed, Waterpepper, Water Pepper: Persicaria hydropiperoides (Synonyms: Persicaria paludicola, Polygonum hydropiperoides, Polygonum hydropiperoides var. adenocalyx, Polygonum hydropiperoides var. asperifolium, Polygonum hydropiperoides var. buschianum, Polygonum hydropiperoides var. digitatum, Polygonum hydropiperoides var. hydropiperoides, Polygonum hydropiperoides var. opelousanum, Polygonum hydropiperoides var. psilostachyum, Polygonum opelousanum, Polygonum opelousanum var. adnocalyx, Polygonum persicarioides)) -
Curltop Ladysthumb, Curltop Knotweed, Dock-leaf Smartweed, Pale Smartweed, Willow Weed: Persicaria lapathifolia (Synonyms: Polygonum incarnatum, Polygonum lapathifolium, Polygonum lapathifolium var. salicifolium, Polygoum linicola, Polygonum nodosum, Polygonum scabrum, Polygonum tomentosum) -
Heartweed, Spotted Ladysthumb, Redshank, Spotted Ladysthumb, Spotted Lady's-thumb, : Persicaria maculosa (Synonym: Polygonum persicaria) -
Pennsylvania Smartweed, Pinkweed: Persicaria pensylvanica (Synonyms: Persicaria bicornis, Persicaria longistyla, Persicaria mississippiensis, Persicaria pensylvanica var. dura, Polygonum bicorne, Polygonum longistylum, Polygonum longistylum var. omissum, Polygonum mexicanum, Polygonum mississippiense, Polygonum mississippiense var. interius, Polygonum pensylvancium var. durum, Polygonum pensylvanicum var. eglandulosum, Polygonum pensylvanicum var. genuinum, Polygonum pensylvanicum var. laevigatum, Polygonum pensylvanicum var. rosiflorum) -
Dotted Smartweed, Water Smartweed: Persicaria puncatata (Synonyms: Polygonum punctatum, Polygonum punctatum var. punctatum) -
Arrowleaf Tearthumb, Arrowvine, Renouee sagitee: Persicaria sagittata (Synonym: Polygonum sagittatum) -
Garden Knotweed, Himalayan Knotweed: Persicaria wallichii (Synonyms: Persicaria wallichii var. wallichii, Polygonum polystachyum) -