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Helianthus silphioides

Nutt.

Rosinweed Sunflower

G4Apparently Secure Found in 3 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
Least concernIUCN
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.157776
Element CodePDAST4N1D0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNLeast concern
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Other Common Names
Ozark Sunflower (EN) rosinweed sunflower (EN) Silphium 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 Date2025-11-24
Change Date2006-02-01
Edition Date2025-11-24
Edition AuthorsK. Crowley, MRO (Annabelle, C. (1992) entered GRank), rev. Soteropoulos (2025)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Helianthus silphioides is a wide-ranging perennial herb found in open, sunny areas with acid soils, including low sandy or alluvial soils near streams, fallow fields, woodland borders, dry upland open woods and savannas, sand and upland prairies, glades, thickets, and roadsides. It occurs in the south-central and southeastern United States from southern Illinois (extirpated), western Kentucky, southern Missouri, and eastern Oklahoma south to Louisiana and Alabama. There are over 100 occurrences, which face threats from conversion of habitat to closed-canopy pine plantations, agriculture, or pastureland, development, rights-of-way maintenance, fire suppression leading to succession, 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 silphioides occurs in the south-central and southeastern United States from southern Illinois (extirpated), western Kentucky, southern Missouri, and eastern Oklahoma south to Louisiana and Alabama (FNA 2006, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be over 350,000 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 100 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 conversion of habitat to closed-canopy pine plantations, agriculture, or pastureland, development, rights-of-way maintenance, fire suppression leading to succession, 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, pers. comm., 1995, NatureServe 2025).
Ecology & Habitat

Habitat

Helianthus silphioides grows in open, sunny areas with acid soils, including low sandy or alluvial soils near streams, fallow fields, woodland borders, dry upland open woods and savannas, sand and upland prairies, glades, thickets, and roadsides (Steyermark 1963, FNA 2006, Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Forest/WoodlandForest EdgeWoodland - HardwoodWoodland - MixedShrubland/chaparralSavannaGrassland/herbaceousOld field
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN4
ProvinceRankNative
MissouriSNRYes
ArkansasSNRYes
AlabamaSNRYes
OklahomaS1Yes
IllinoisSXYes
KentuckyS1Yes
MississippiS4Yes
TennesseeS2Yes
LouisianaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownUnknown
2 - Agriculture & aquacultureUnknownUnknownUnknown
2.1 - Annual & perennial non-timber cropsUnknownUnknownUnknown
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 (3)
Arkansas (3)
AreaForestAcres
Blue MountainOuachita National Forest9,755
Clifty CanyonOzark-St. Francis National Forest1,963
Pedestal RocksOzark-St. Francis National Forest21,957
References (11)
  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. Kral, Dr. Robert. Dept. of General Biology, Vanderbilt University, Nashville, TN. Pers. comm. of April 4 with Kathy Crowley, MRO.
  6. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  8. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  9. Steyermark, J. 1963. Flora of Missouri. University of Iowa Press, Ames.
  10. Vlaszek, E.F. 1985. General Questionnaire for Helianthus silphioides Nutt.
  11. 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).