A limited amount of habitat in two Virginia counties and six Missouri counties make up this species' entire global range. There are currently 61 documented occurrences, although 4 or fewer may not be extant, with the majority in Missouri as of 2006. The Virginia occurrences are restricted to small, discrete areas around sinkholes, and occupying, in total, less than 20 acres (8 ha). Missouri occurrences occupy ca. 11 acres within both discrete and less discrete wetland habitat. Six Virginia occurrences are currently protected by being on National Forest land or within state preserves. Only 9 Missouri occurrences have some protection although not complete. Sites in both states are threatened by drainage and residential development.
Habitat modification is the primary threat to H. virginicum. Some of these modifications include residential development, filling of wetland habitats, and other disruptions of hydrology. Cattle grazing and mowing at moderate levels can be beneficial, ho
Known from approximately 25-30 sites in Virginia and at least as many sites in Missouri. The number of individual plants at each site varies from year to year, from a few plants to hundreds of thousands (NatureServe)
A number of studies have been conducted on Helenium virginicum. Common garden and transplant studies distinguished H. virginicum from Canadian narrow-leaved H. autumnale (Knox, et. al. 1995). Phylogenetic analyses using ITS sequence evidence placed H. virginicum occurring in Missouri in a monophyletic group with H. virginicum occurring in Virginia (Simurda and Knox 2000). A nine-year demographic study of H. virginicum in Virginia led to the conclusion that the rarity of the species may result from it being limited to refugia where competition is reduced by a stressful soil and variable hydroperiod (Knox 1997). The species is thought to be self-incompatible, which may put small populations at risk of local extinction (Messmore and Knox 1997). A restoration project to establish populations of H. virginicum in protected areas began in 2002 (Rimer and McCue, in review). A survey of suitable habitat in Missouri located >25 previously unknown populations of H. virginicum (Rimer and Summers, in review)
Current management practices unknown.
Survey for additional sites of Virginia sneezeweed throughout the Lower Missouri Ozarks. Evaluate new sites for potential threats to Virginia sneezeweed populations. Monitor Virginia sneezeweed population health at known sites.
Collection and storage of seed from populations in both Virginia and Missouri.
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