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Helianthus radula

(Pursh) Torr. & Gray

Pineland Sunflower

G5Secure Found in 3 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.148289
Element CodePDAST4N180
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Other Common Names
Rayless Sunflower (EN) rayless sunflower (EN) Roundleaf Sunflower (EN) Stiff 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 Date2025-11-25
Change Date2025-11-25
Edition Date2025-11-25
Edition AuthorsSoteropoulos (2025)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Helianthus radula is a wide-ranging perennial herb found in open pine barrens, longleaf pine sandhills, dryish savannas, dry pine flatwoods, wet flatwoods, on roadsides, and in forest clearings. It is endemic to the southeastern United States from southern South Carolina south to southern peninsular Florida and west to southeastern Louisiana. There are over 300 occurrences, which potentially face threats from development, conversion to pine plantation, rights-of-way maintenance, logging, 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 secure.
Range Extent Comments
Helianthus radula is endemic to the southeastern United States from southern South Carolina south to southern peninsular Florida and west to southeastern Louisiana (FNA 2006, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be over 400,000 square kilometers using herbarium specimens and photo-based observations documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens and photo-based observations documented between 1994 and 2025, it is estimated that there are over 300 occurrences rangewide (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, this species is potentially threatened by development, conversion to pine plantation, rights-of-way maintenance, logging, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range and large number of occurrences.
Ecology & Habitat

Habitat

Helianthus radula grows in sandy, open pine barrens, longleaf pine sandhills, dryish savannas, dry pine flatwoods, wet flatwoods, on roadsides, and in forest clearings (FNA 2006, Keener et al. 2025, Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Woodland - ConiferWoodland - MixedSavanna
Other Nations (1)
United StatesN5
ProvinceRankNative
LouisianaS4Yes
FloridaS4Yes
South CarolinaS1Yes
AlabamaSNRYes
MississippiS4Yes
GeorgiaSNRYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (3)
Florida (3)
AreaForestAcres
Gum BayApalachicola National Forest11,645
Long BayApalachicola National Forest5,726
SavannahApalachicola National Forest1,927
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. 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.
  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).