Checklist » Polygonaceae » Persicaria hydropiperoides
Last updated 10/5/2010 by David Giblin.
Persicaria hydropiperoides (Michx.) Small[FNA5, HC2]
swamp smartweed

Publication: Fl. S.E. U.S. 378. 1903.

Origin: Native

selected vouchers: WTU

Notes: FNA5: "The extreme variability in Persicaria hydropiperoides is reflected in its extensive synonymy. Among the segregates most often recognized in floras and checklists is P. opelousana, which C. B. McDonald (1980) showed to be broadly sympatric and highly interfertile with P. hydropiperoides. Consistent with this conclusion, R. S. Mitchell (1971) found that P. hydropiperoides and P. opelousana are unique among native North American smartweeds in consistently possessing multicellular plate-glands on the abaxial surface of their leaves. Such glands also are found on P. maculosa, an introduced European species.

Herbarium specimens of Persicaria hydropiperoides sometimes are misidentified as P. maculosa, especially when the roots are missing. The former species may be distinguished reliably by its achenes all trigonous (trigonous and biconvex achenes are mixed in the inflorescences of P. maculosa) and bristles on the margins of the ocreae that average longer. M. L. Fernald (1922c) reported hybrids with P. robustior from Nova Scotia."

References: (none)

Synonyms & Misapplied Names:
Persicaria opelousana (Riddell ex Small) Small
Persicaria paludicola Small
Polygonum hydropiperoides Michx.[HC, ILBC4, JPM]
Polygonum hydropiperoides Michx. var. adenocalyx (Stanford) Gleason
Polygonum hydropiperoides Michx. var. asperifolium Stanford
Polygonum hydropiperoides Michx. var. breviciliatum Fernald
Polygonum hydropiperoides Michx. var. buschianum Stanford
Polygonum hydropiperoides Michx. var. digitatum Fernald
Polygonum hydropiperoides Michx. var. hydropiperoides[HC]
Polygonum hydropiperoides Michx. var. opelousanum (Riddell ex Small) W. Stone
Polygonum hydropiperoides Michx. var. psilostachyum H. St. John
Polygonum opelousanum Riddell ex Small
Polygonum opelousanum Riddell ex Small var. adenocalyx Stanford