Helianthus angustifolius L.
Swamp Sunflower, Narrowleaf Sunflower, Narrow-leaved Sunflower
Asteraceae (Aster Family)
Synonym(s): Helianthus angustifolius var. planifolius
USDA Symbol: hean2
Narrowleaf Sunflower is a member of the family Asteraceae, which includes herbs, sometimes shrubs or vines, rarely trees, with simple or compound, alternate or opposite leaves. Flowers small, but organized into larger heads resembling a single, radially symmetrical flower cupped by a ring of green bracts. Flower-like heads: tiny, radially symmetrical central flowers form the disc; larger flowers around the edge; the rays, strap-shaped and resembling petals (however, all flowers in one head may be disc flowers or rays.)
In this large worldwide family there are about 920 genera and 19,000 species. Cosmos, Sunflower, Zinnia, Dahlia, and many others are grown as ornamentals. Lettuce, Sunflowers, and Artichokes provide food. Safflower oil is obtained from this family.
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Size Notes: Up to about 5 feet tall.
Leaf: Dark Green
Flower: Flowers 2 inches
Fruit: Fruit is a cypsela (pl. cypselae). Though technically incorrect, the fruit is often referred to as an achene.
Bloom InformationBloom Color: Yellow
Bloom Time: Aug , Sep , Oct , Nov
DistributionUSA: AL , AR , DC , DE , FL , GA , IL , IN , KY , LA , MD , MO , MS , NC , NJ , NY , OH , OK , PA , SC , TN , TX , VA , WV
Native Habitat: Flood plains, bottomland
Growing ConditionsWater Use: Medium
Light Requirement: Part Shade
Soil Moisture: Wet
CaCO3 Tolerance: Medium
Soil Description: Sandy, Sandy Loam, Medium Loam, Clay Loam, Clay, Acid-based
BenefitUse Ornamental: Bog or pond area, Blooms ornamental, Color
Conspicuous Flowers: yes
Value to Beneficial InsectsSpecial Value to Native Bees
This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.
PropagationPropagation Material: Seeds
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National Wetland Indicator Status
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Delaware Nature Society - Hockessin, DE
Crosby Arboretum - Picayune, MS
Wildflower Center Seed BankLBJWC-1250 Collected 2008-11-05 in Anderson County by Lady Bird Johnson Wildflower Center
BibliographyBibref 1620 - Gardening with Native Plants of the South (Reprint Edition) (2009) Wasowski, S. with A. Wasowski
Bibref 318 - Native Texas Plants: Landscaping Region by Region (2002) Wasowski, S. & A. Wasowski
Search More Titles in Bibliography
Web ReferenceWebref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Research LiteratureReslit 248 - Physiological mechanisms of drought resistance in four native ornamental perennials (1994) D. S. Chapman and R. M. Auge
Reslit 391 - High genetic diversity in a rare and endangered sunflower as compared to a common congener (2006) J. R. Ellis, C. H. Pashley, J. M. Burke and D. E. ...
Reslit 917 - Effects of Fire on Plant Community Composition of North Florida Second Growth Pineland (1992) D. W. Mehlman
Reslit 1061 - EST databases as a source for molecular markers: Lessons from Helianthus (2006) C. H. Pashley, J. R. Ellis, D. E. McCauley and J. ...
Reslit 1261 - Oil concentration and fatty acid profile of wild Helianthus species from the southeastern United States (2010) G. J. Seiler, T. J. Gulya and G. Kong
This information was provided by the Florida WIldflower Foundation.
Search More Titles in Research Literature
From the ArchiveWildflower Newsletter 1986 VOL. 3, NO.1 - Library and Clearinghouse Serve the Nation, What is a Weed, More than Just a Pre...
Additional resourcesUSDA: Find Helianthus angustifolius in USDA Plants
FNA: Find Helianthus angustifolius in the Flora of North America (if available)
Google: Search Google for Helianthus angustifolius
MetadataRecord Modified: 2022-12-28
Research By: TWC Staff