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Helianthus microcephalus

Torr. & Gray

Small Woodland Sunflower

G5Secure Found in 13 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.160285
Element CodePDAST4N0W0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Other Common Names
Small-headed Sunflower (EN) small woodland 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 Date2025-11-13
Change Date1985-10-11
Edition Date2025-11-13
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 microcephalus is a wide-ranging perennial herb found in open woodlands, rocky slopes, wood margins, barrens, powerline clearings, and roadsides. It occurs in the eastern United States from Pennsylvania west to Michigan (presumed extirpated), south to the Florida panhandle and southeastern Louisiana. There are over 600 occurrences, which potentially face threats from development, rights-of-way maintenance, forest management practices, 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 secure.
Range Extent Comments
Helianthus microcephalus occurs in the eastern United States from Pennsylvania west to Michigan (presumed extirpated), south to the Florida panhandle and southeastern Louisiana. It is introduced in New Jersey and Connecticut (FNA 2006, Native Plant Trust 2025, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be over 1.1 million 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 600 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, rights-of-way maintenance, forest management practices, fire suppression, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, and no obvious intrinsic vulnerabilities.
Ecology & Habitat

Habitat

Helianthus microcephalus grows in open, dry to dry-mesic (rarely mesic) pine-hardwoods and other woodlands, rocky slopes, openings and clearings, wood margins, barrens, powerline clearings, and shaded roadsides on both acidic and basic substrates (FNA 2006, LeGrand et al. 2025, Virginia Botanical Associates 2025, Weakley and the Southeastern Flora Team 2025).

Reproduction

This species flowers from late summer (July) to fall (October) (FNA 2006, Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Forest/WoodlandForest EdgeWoodland - HardwoodWoodland - MixedBarrens
Other Nations (1)
United StatesN5
ProvinceRankNative
IllinoisSNRYes
KentuckyS5Yes
West VirginiaS5Yes
OhioSNRYes
LouisianaSNRYes
FloridaSNRYes
GeorgiaSNRYes
VirginiaS4Yes
PennsylvaniaS4Yes
ArkansasSNRYes
IndianaSNRYes
New JerseySNANo
ConnecticutSNANo
TennesseeSNRYes
MississippiSNRYes
AlabamaSNRYes
South CarolinaS5Yes
MichiganSXYes
North CarolinaS5Yes
MissouriSNRYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (13)
Georgia (3)
AreaForestAcres
Kelly RidgeChattahoochee National Forest8,325
Pink KnobChattahoochee National Forest12,127
Sarah's CreekChattahoochee National Forest6,888
Indiana (1)
AreaForestAcres
Mogan RidgeHoosier National Forest8,435
Kentucky (1)
AreaForestAcres
WolfpenDaniel Boone National Forest2,835
North Carolina (5)
AreaForestAcres
Harper CreekPisgah National Forest7,325
Jarrett CreekPisgah National Forest7,485
Linville Gorge AdditionPisgah National Forest2,809
Lost CovePisgah National Forest5,944
Mackey MountainPisgah National Forest5,934
Tennessee (2)
AreaForestAcres
Big Laurel Branch AdditionCherokee National Forest5,577
Stone MountainCherokee National Forest5,367
Virginia (1)
AreaForestAcres
North Fork PoundJefferson National Forest4,757
References (10)
  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. 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).
  6. Native Plant Trust. 2025. Go Botany website. Online. Available: https://gobotany.nativeplanttrust.org (accessed 2025).
  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. Virginia Botanical Associates. 2025. Digital Atlas of the Virginia Flora. Virginia Botanical Associates, Blacksburg. Online. Available: <a href="http://www.vaplantatlas.org/">http://www.vaplantatlas.org</a> (accessed 2025).
  10. 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).