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Helianthus smithiorum

Heiser

Smith's Sunflower

G3Vulnerable Found in 1 roadless area NatureServe Explorer →
G3VulnerableGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.133563
Element CodePDAST4N1F0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Synonyms
Helianthus smithiiHeiser
Other Common Names
Smith's sunflower (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
Helianthus smithii might be a hybrid of H. microcephalus and H. strumosus (FNA vol. 21, 2006). "The epithet must be corrected to "smithiorum", as Heiser intended it to commemorate two Smiths" (Weakley 2025).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-11-20
Change Date2025-11-20
Edition Date2025-11-20
Edition AuthorsMaybury, K., rev. K. Gravuer (2006), rev. A. Schotz (2007), rev. Soteropoulos (2025)
Threat ImpactUnknown
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Helianthus smithiorum is a perennial herb found in open, oak-hickory-pine upland woods and thickets. It is endemic to the southeastern United States from northern and west-central Georgia, eastern Alabama, and southeastern Tennessee, but possibly occurring in western North Carolina. There are at least 30 occurrences, which face threats from development, conversion to pine plantations, rights-of-way maintenance, forestry management practices, succession from lack of disturbance (primarily fire suppression), invasive species, and other threats in some places. Research is needed to determine the validity of this taxon, population dynamics, and associated geology or other factors that may limit the abundance of this taxon. Monitoring of populations should be conducted to improve our understanding of reproduction, plant abundance, threats, and trends, as well as continuing conservation measures to protect the taxon.
Range Extent Comments
Helianthus smithiorum is endemic to the southeastern United States from northern and west-central Georgia, eastern Alabama, and southeastern Tennessee, where it has been documented in the following counties by state: Alabama (Blount, Calhoun, Cherokee, Clay, Cleburne, Jackson, Lee, Randolph, and Talladega counties), Georgia (Bartow, Chattahoochee, Dade, Habersham, Muscogee Stephens, and Rabun counties), and Tennessee (Blount, Franklin, Grundy, Marion, Polk, and Sequatchie counties) (FNA 2006, Keener et al. 2025, NatureServe 2025, Shaw 2025, Weakley and the Southeastern Flora Team 2025). It may also be in western North Carolina (Alexander County) based on a specimen found in 2010 (LeGrand et al. 2025). Range extent was estimated to be approximately 73,000 square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are at least 30 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, this species is threatened by development, conversion to pine plantations, rights-of-way maintenance, forestry management practices, succession from lack of disturbance (primarily fire suppression) reducing forest openings, invasive species, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species (Kral 1983, Southern Appalachian Species Viability Project 2002, NatureServe 2025).
Ecology & Habitat

Diagnostic Characteristics

Can be distinguished from H. microcephalus (and a number of other Helianthus species) by its narrowly lance-shaped to linear-lance-shaped leaves with one main nerve (as opposed to lance-shaped to egg-shaped leaves with three main nerves at the base). Also distinguished from H. microcephalus by its petioles less than 1.5 cm long and its nearly hairless (as opposed to covered with fine, dense, matted hairs) leaf undersides. Can be distinguished from H. strumosus by its smaller flower heads with 6-9 ray florets each (as opposed to 10-20) and by its leaves 1 - 1.8 cm in width (as opposed to 2 - 10 cm). Can be distinguished from H. verticillatus by its opposite or alternate (as opposed to whorled) leaves. Can be distinguished from H. laevigatus and H. eggertii by its light to dark green (as opposed to grayish or bluish green) leaf blades. H. laevigatus also lacks resin dots on the leaf undersides.

Habitat

This taxon grows in open, oak-hickory-pine upland woods and thickets in well-drained, dryish sands, sandy loams, or sandy clay loams (Kral 1983, FNA 2006, Weakley and the Southeastern Flora Team 2025). It prefers moderately sized forest openings (Kral 1983), and at least one collection has been in association with a dolomite glade (Kral 62432, BRIT:VDB) and one collection in rocky limestone woods (Kral 62802, BRIT: VDB) (SEINet 2025).

Ecology

This species is shaded out when canopies close (Kral 1983).

Reproduction

This taxon flowers in late summer (August) to fall (September) (FNA 2006, Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Forest/WoodlandForest - MixedForest EdgeWoodland - MixedShrubland/chaparralBarrens
Other Nations (1)
United StatesN3
ProvinceRankNative
North CarolinaSUYes
GeorgiaS1Yes
AlabamaS2Yes
TennesseeS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownUnknown
2 - Agriculture & aquacultureUnknownUnknownUnknown
2.2 - Wood & pulp plantationsUnknownUnknownUnknown
4 - Transportation & service corridorsUnknownUnknownUnknown
5 - Biological resource useUnknownUnknownUnknown
5.3 - Logging & wood harvestingUnknownUnknownUnknown
7 - Natural system modificationsUnknownUnknownUnknown
7.1 - Fire & fire suppressionUnknownUnknownUnknown
7.1.2 - Suppression in fire frequency/intensityUnknownUnknownUnknown
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownUnknown
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownUnknown
8.1.1 - Unspecified speciesUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (1)
Alabama (1)
AreaForestAcres
Oakey MountainTalladega National Forest6,129
References (21)
  1. Allison, J. R. and T. E. Stevens. 2001. Vascular flora of the Ketona Dolomite outcrops in Bibb County, Alabama. Castanea 66(1&2): 154-205.
  2. Cronquist, A. 1977. Notes on the Asteraceae of the southeastern United States. Brittonia 29:217-225.
  3. Flora of North America Editorial Committee (FNA). 2006c. Flora of North America north of Mexico. Vol. 21. Magnoliophyta: Asteridae, part 8: Asteraceae, part 3. Oxford Univ. Press, New York. xxii + 616 pp.
  4. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  5. Heiser, C.B., Jr., with D.M. Smith, S.B. Clevenger, and W.C. Martin, Jr. 1969. The North American sunflowers (Helianthus). Memoirs of the Torrey Botanical Club 22(3). 218 pp.
  6. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  7. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  8. Keener, B.R., A.R. Diamond, T.W. Barger, L.J. Davenport, P.G. Davison, S.L. Ginzbarg, C.J. Hansen, D.D. Spaulding, J.K. Triplett, and M. Woods. 2025. Alabama Plant Atlas. [S.M. Landry and K.N. Campbell (original application development), Florida Center for Community Design and Research. University of South Florida]. University of West Alabama, Livingston, Alabama.
  9. Kral, R. 1983c. A report on some rare, threatened, or endangered forest-related vascular plants of the South. U.S. Dept. of Agriculture Forest Service Technical Publication R8-TP2, Athens, GA. 1305 pp.
  10. Laparra, H., P. Stoeve, and P. Ivanov. 1997. Plant regeneration from different explants in <i>Helianthus smithii</i> Heiser. Plant Cell Reports 16 (10): 692-695.
  11. LeGrand, H., B. Sorrie, and T. Howard. 2025. Vascular Plants of North Carolina [Internet]. Raleigh (NC): North Carolina Biodiversity Project and North Carolina State Parks. Online. Available: https://auth1.dpr.ncparks.gov/flora/index.php (accessed 2025).
  12. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  13. Patrick, T. 1998, 2003 last update. Georgia Plant Conservation Alliance Conservation Project: Historic Species Search Project. Online. Available: http://www.uga.edu/gpca/project4.html (Accessed 2006).
  14. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  15. Seiler, G. J., and T. J. Gulya, Jr. 2005. Recent explorations to recover seed of rare and interesting <i>Helianthus</i> species and future explorations. Proceedings Sunflower Research Workshop. 27th Sunflower Research Workshop, January 12-13, 2005, Fargo, ND. Online. Available: http://www.sunflowernsa.com/research/research-workshop/documents/seiler_recoveringseeds_05.pdf
  16. Shaw, J. 2025. Tennessee-Kentucky Plant Atlas. [S.M. Landry and K.N. Campbell (original application development), USF Water Institute. University of South Florida]. University of Tennessee at Chattanooga, Austin Peay State University, University of Michigan, Furman University, and Kentucky State Nature Preserves Commission. Online. Available: https://tennessee-kentucky.plantatlas.usf.edu/ [accessed 2025].
  17. Southern Appalachian Species Viability Project. 2002. A partnership between the U.S. Forest Service-Region 8, Natural Heritage Programs in the Southeast, NatureServe, and independent scientists to develop and review data on 1300+ regionally and locally rare species in the Southern Appalachian and Alabama region. Database (Access 97) provided to the U.S. Forest Service by NatureServe, Durham, North Carolina.
  18. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  19. Weakley, A.S. 1996. Flora of the Carolinas and Virginia: working draft of 23 May 1996. The Nature Conservancy, Southeast Regional Office, Southern Conservation Science Dept., Chapel Hill, North Carolina. Unpaginated.
  20. Weakley, A.S., and Southeastern Flora Team. 2025. Flora of the southeastern United States Web App. Edition of February 18, 2025. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. Online. Available: https://fsus.ncbg.unc.edu (accessed 2025).
  21. Wofford, B.E., and R. Kral. 1993. Checklist of the vascular plants of Tennessee. Sida Botanical Miscellany No. 10, Botanical Research Institute of Texas, Fort Worth. 66 pp.