OF THE CAROLINAS & GEORGIA

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



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.

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913    pnd_hegi_001_lvd

        

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

JK Marlow    jkm140917_832

September    Greenville County    SC

Swamp Rabbit Trail

Phyllaries not conspicuously graduated & imbricate, usually loose or spreading, per Weakley's Flora.


click here to see other plants that look similar to this COMPARE involucral bracts of Sunflowers

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

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).

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

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).

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

JK Marlow    jkm140917_837

September    Greenville County    SC

Swamp Rabbit Trail

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

JK Marlow    jkm140917_838

September    Greenville County    SC

Swamp Rabbit Trail

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

JK Marlow    jkm140917_840

September    Greenville County    SC

Swamp Rabbit Trail

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

JK Marlow    jkm140917_842

September    Greenville County    SC

Swamp Rabbit Trail

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

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).

image of Helianthus giganteus, Tall Sunflower, Swamp Sunflower, Tuberous Sunflower, Giant Sunflower

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

 

Find by SCIENTIFIC NAME:

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)

map
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.

Click here to see a map showing all occurrences known to SERNEC, a consortium of southeastern herbaria. (Zoom in to see more detail.)

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!



 


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