Polygonum aviculare L.

Locations ofPolygonum aviculare L. in Virginia

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Botanical Name
Polygonum aviculare L.
Common Name
Prostrate Knotweed, Knotgrass
Polygonum aviculare var. aviculare; Polygonum aviculare var. buxiforme (Small) Costa & Tardiff; Polygonum aviculare var. depressum (Meisn.) Arcang.; Polygonum aviculare var. neglectum (Bess.) Arcang.; Polygonum buxiforme Small
Flora of Virginia Name/Status
Polygonum aviculare L.
In the lumped treatment here and in Flora of Virginia, the name Polygonum aviculare represents an assemblage of predominantly selfing annuals with sympatric distributions, intergrading morphologies, and multiple ploidy levels. Costea et al. (2005) in FNA attributes four subspecies to Virginia; Flora of the Southeastern U.S. attributes three subspecies and elevates the fourth FNA subspecies (buxiforme) to species rank. Currently, individual maps for these segregates are not feasible since very few herbarium specimens have been identified as such, virtually no data exists about their in-state distribution and habitats, and it's not clear how easily they can be distinguished. Based on a preliminary examination of annotated specimens at VPI, very good specimens collected with the necessary flowering or fruiting characters were required to see the purported differences in some of the subspecies – and even then it was very difficult.
Weedy fields, roadsides, lawns, and cultivated ground; often in barren, compacted soils. Common throughout.
Native Status

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