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Helianthus heterophyllus

Nutt.

Wetland Sunflower

G4Apparently Secure Found in 4 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
Identity
Unique IDELEMENT_GLOBAL.2.138457
Element CodePDAST4N0Q0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Other Common Names
Savanna Sunflower (EN) variableleaf sunflower (EN) Variableleaf 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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-11-11
Change Date1998-01-26
Edition Date2025-11-11
Edition AuthorsSoteropoulos (2025)
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Helianthus heterophyllus is a wide-ranging perennial herb found in wet sandy soils of pine savannas and seepage bogs. It is endemic to the southeastern United States in the Atlantic and Gulf coastal plains from North Carolina south to Florida panhandle and west to southeastern Louisiana. There are over 150 occurrences, which face threats from development, conversion to pasture and grazing, conversion to pine plantation and silvicultural activities, rights-of-way maintenance, fire suppression, invasive species, and other threats in some places. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, and broad habitat preferences, this species is considered apparently secure.
Range Extent Comments
Helianthus heterophyllus is endemic to the southeastern United States in the Atlantic and Gulf coastal plains from North Carolina south to Florida panhandle and west to southeastern Louisiana (FNA 2006, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be less than 400,000 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 over 150 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 pasture and grazing, conversion to pine plantation and silvicultural activities, rights-of-way maintenance, fire suppression, 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 (NatureServe 2025).
Ecology & Habitat

Habitat

Helianthus heterophyllus grows in wet sandy soils of pine savannas and seepage bogs (FNA 2006, Weakley and the Southeastern Flora Team 2025).

Reproduction

This species flowers from late summer (August) to fall (October) (FNA 2006, Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Savanna
Palustrine Habitats
HERBACEOUS WETLANDFORESTED WETLANDBog/fen
Other Nations (1)
United StatesN4
ProvinceRankNative
MississippiS3Yes
North CarolinaS3Yes
GeorgiaS1Yes
South CarolinaS3Yes
FloridaS3Yes
LouisianaSNRYes
AlabamaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownUnknown
2 - Agriculture & aquacultureUnknownUnknownUnknown
2.2 - Wood & pulp plantationsUnknownUnknownUnknown
2.3 - Livestock farming & ranchingUnknownUnknownUnknown
4 - Transportation & service corridorsUnknownUnknownUnknown
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 (4)
Florida (3)
AreaForestAcres
Gum BayApalachicola National Forest11,645
Long BayApalachicola National Forest5,726
SavannahApalachicola National Forest1,927
North Carolina (1)
AreaForestAcres
Catfish Lake NorthCroatan National Forest11,299
References (8)
  1. 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.
  2. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  3. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  4. 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.
  5. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  6. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  7. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  8. 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).