Helianthus verticillatus Small

Locations ofHelianthus verticillatus Small in Virginia

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Botanical Name
Helianthus verticillatus Small
Common Name
Whorled Sunflower
Flora of Virginia Name/Status
Not in Flora of Virginia
Known from two locations where circumstances strongly indicate horticultural origin. In each case, the placement of the colonies seems planned and the habitat implausible. The species is available as a "niche" product in the nursery trade, so a planted origin is possible. However, Moore et al (Castanea 86(2) 2021) report unique genetic variation in the Franklin County material and evidence that the population experienced a genetic bottleneck. The Roanoke County plants have not been sampled molecularly. For now we are treating the Franklin population as of Uncertain origin and the Roanoke population as Introduced.
At the Franklin County site, the small colonies occur adjacent to one another at the edge of a mowed, mid-elevation upland field. The Roanoke population consists of several large colonies of similar size, each occurring roughly equidistant from one another along a boardwalk through a eutrophic wetland. The lack of colonies elsewhere in this wetland complex is suspicious.
Native Status
Not Specified

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