Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Asterids: Campanulids: Asterales
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Helianthus giganteus
FAMILY
Asteraceae
Go to FSUS key
Dig deeper at SERNEC, a consortium of southeastern herbaria.
Read more about Tall Sunflower at Vascular Plants of North Carolina.
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Helianthus giganteus
FAMILY
Asteraceae
SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21 (2006)
Helianthus giganteus
SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 179-65-021:
Helianthus giganteus FAMILY Asteraceae
INCLUDING Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus alienus
INCLUDING Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus giganteus
INCLUDING Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus validus
COMMON NAME:
Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower
To see larger pictures, click or hover over the thumbnails.
)
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913 pnd_hegi_001_lvd
)
JK Marlow jkm140917_832
September Greenville County SC
Swamp Rabbit Trail
Phyllaries not conspicuously graduated & imbricate, usually loose or spreading, per Weakley's Flora.
COMPARE
involucral bracts of Sunflowers
)
JK Marlow jkm140917_833
September Greenville County SC
Swamp Rabbit Trail
Stem hairy, reddish; leaves narrowly lanceolate, tapering to a short petiole, per Wildflowers of the Southern Mountains (Smith, 1998).
)
JK Marlow jkm140917_836
September Greenville County SC
Swamp Rabbit Trail
Leaves triplinerved (with a prominent lateral pair of veins near the base), per Weakley's Flora (2012).
)
JK Marlow jkm140917_837
September Greenville County SC
Swamp Rabbit Trail
)
JK Marlow jkm140917_838
September Greenville County SC
Swamp Rabbit Trail
)
JK Marlow jkm140917_840
September Greenville County SC
Swamp Rabbit Trail
)
JK Marlow jkm140917_842
September Greenville County SC
Swamp Rabbit Trail
)
JK Marlow jkm140917_843
September Greenville County SC
Swamp Rabbit Trail
May grow to 10', but flowers are proportionately small, often < 2" diameter, per Wildflowers of the Southern Mountains (Smith, 1998).
)
Richard and Teresa Ware rtw_h_giganteus_7
October
Ray florets 12-20, oft pale yellow. Disc florets' lobes yellow; anthers dark, per Flora of North America.
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Helianthus giganteus
FAMILY
Asteraceae
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Helianthus giganteus
FAMILY
Asteraceae
SYNONYMOUS WITH
Flora of North America north of Mexico, vol. 19-20-21
Helianthus giganteus
SYNONYMOUS WITH
VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 179-65-021:
Helianthus giganteus
FAMILY
Asteraceae
INCLUDING
Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus alienus
INCLUDING
Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus giganteus
INCLUDING
Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus validus
2737
Forb
Perennial
Habitat: bog edges, moist thickets, ditches, per Weakley's Flora
Native to the Carolinas & Georgia
Common (uncommon in Mountains south of NC, rare in Coastal Plain south of VA)
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.
LEAVES:
Simple
Mostly alternate, lowermost opposite
Petioles .3-1.5cm long
FLOWER:
Summer/Fall
Rays: Pale yellow
Disc: Yellow
Inferior ovary
Disc flowers bisexual & fertile/ Ray flowers pistillate but sterile
FRUIT:
Summer/Fall
Blackish/Brown
Achene
TO LEARN MORE about this plant, look it up in a good book!
- Wildflowers of the Atlantic Southeast (Cotterman, Waitt, & Weakley, 2019) p285
- Wildflowers of Tennessee (Carman, 2005) p305
- Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005) p355
- Wildflowers of the Southern Mountains (Smith, 1998) p193
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