Regularity: Regularly occurring
Global Range: Known only from Alabama (Cherokee Co.), Georgia (Floyd Co.), and Tennessee (Madison and McNairy Cos.). It was reported from Louisiana but this is based on a misattribution (Matthews et al. 2002).
Differs from H. grosseserratus in its whorled leaves; the leaves of H. grosseserratus are typically arranged in an alternating pattern. Differs from H. angustifolius in its wider leaves and pure yellow disk flowers; H. angustifolius has reddish disk flowers. Differs from H. giganteus in having only the midvein prominent on the leaves; H. giganteus has lateral veins evident.
Catalog Number: US 215119
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: ; Card file verified by examination of alleged type specimen
Preparation: Pressed specimen
Collector(s): S. M. Bain
Year Collected: 1892
Locality: Henderson., Chester, Tennessee, United States, North America
Comments: A narrow habitat specialist occurring in remnant wet prairie areas and calcareous barrens, in moist, prairie-like openings in woodlands and along adjacent creeks. Soils are sandy clays which are alkaline, high in organic matter, and seasonally wet. Some associated plant species, including Schizachyrium scoparium, Sorghastrum nutans, Andropogon gerardii, and Panicum virgatum, suggest a strong prairie affinity. Other associates include Carex cherokeensis, Sporobolus heterolepis, Physostegia virginiana, Silphium terebinthinaceum, Pycnanthemum virginianum, Symphyotrichum novae-angliae, Hypericum sphaerocarpum, H. angustifolius, Helenium autumnale, and Marshallia mohrii.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 20
Comments: Five population groups are currently known extant, two in Alabama, one (with three sub-populations) in Georgia, and two in Tennessee (Norquist 2005; A. Bishop, pers. comm., 2007); in addition, there is the historical type collection from Tennessee in 1892, which has not been relocated despite searches.
Molecular Biology and Genetics
Barcode data: Helianthus verticillatus
Statistics of barcoding coverage: Helianthus verticillatus
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Known from five population groups, all in remnant prairie habitat in Alabama, Georgia, and Tennessee. All known populations contain a relatively small number of genetic individuals. Threats include incompatible right-of-way maintenance, road construction, agriculture and residential development, industrial forestry practices, and fire suppression. In the absence of natural disturbance, active management is needed to reduce competition and shading. These plants are treated as a hybrid by Kartesz (1999), but as a species by the U.S. Fish and Wildlife Service, Matthews et al. (2002), and Flora of North America Editorial Committee (2006).
Environmental Specificity: Very narrow. Specialist or community with key requirements scarce.
Comments: Known only from prairie-like openings that were presumably maintained by occasional natural fires (Norquist 2005). Currently dependent upon active management of habitat to reduce competition and shading (Call 2009).
Status: Proposed Endangered
Lead Region: Southeast Region (Region 4)
For most current information and documents related to the conservation status and management of Helianthus verticillatus, see its USFWS Species Profile
Global Short Term Trend: Unknown
Comments: Most sites recently discovered. Its wet prairie habitat exists mainly as remanants along rights-of-way (Norquist 2005). Plants at some sites have apparantly been destroyed by road maintainace activities.
Global Long Term Trend: Unknown
Comments: Most sites recently discovered. Rarity due to habitat loss. Its wet prairie habitat was more extensive before European settlement, fire suppression, and conversion to farmland; much of this habitat has been degraded or destroyed due to agricultural, silvicultural, and residential development (Matthews et al. 2002, Call 2009). Most remaining wet prairies are remnants along rights-of-way where succession is artificially impeded (Call 2009).
Degree of Threat: High - medium
Comments: Threatened by industrial forestry practices such as routine timber harvest or conversion to pine monoculture (Norquist 2005). The Alabama populations have been impacted by timber harvesting in the past (Call 2009). However, the magnitude of the threat from forestry may not be as great as believed in the past; the Georgia population continues to be managed in accordance with its conservation easement, and one of the Alabama populations appears to have responded well to canopy removal from a timber harvest (Call 2009). Plants along roadsides, powerlines, and railroad rights-of-way are threatened by incompatible right-of-way improvement and maintenance including by herbicide usage and poorly timed mowing (Norquist 2005; A. Bishop pers. comm., 2007). The Alabama populations have been impacted by poorly timed right-of-way maintenance in the past (Call 2009). One site, in a natural prairie, could be threatened if fertilizer is used there, or non-native grasses are introduced, in an attempt to increase hay production (Norquist 2005). Also threatened by crop production, including spraying of herbicides and insecticides, and residential development (Norquist 2005; A. Bishop pers. comm., 2007). Fire suppression is a threat because the taxon depends on the maintenance of prairie-like openings for its survival (Norquist 2005). Habitat has been degraded due to the invasion of woody competitors (J. Allison, pers. comm., 1999 in Norquist 2005). Active management of habitat is needed to reduce competition and shading (Call 2009). Helianthus verticillatus could potentially be threatened by collection as it is attractive and in visible locations (Norquist 2005).
Biological Research Needs: Determine possible limiting factors for low fitness at the Georgia site (Call 2009).
Names and Taxonomy
Comments: The U.S. Fish and Wildlife Service (Call 2009) accepts this taxon as a species in considering it a candidate for federal listing; Matthews et al. (2002) and Flora of North America Editorial Committee (2006) also treat it as a species. Two supporting studies are cited by the USFWS: (1) morphological studies and root-tip chromosome counts which showed it to be a distinct, fertile diploid (Matthews et al. 2002); and (2) comparative genetic studies with its putative parents (H. grosserratus and H. angustifolius), which showed that it does not exhibit a mixture of parental alleles at nuclear loci and does not share chloroplast DNA haplotype with either of its putative parents (Ellis et al. 2006). In contrast, the Kartesz checklists (1994 and 1999) treat this taxon as a hybrid between Helianthus angustifolius and H. grosseserratus, following earlier treatments written when it was known from only the type specimen.
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