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 decapetalus   FAMILY Asteraceae   Go to FSUS key



SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Helianthus decapetalus   FAMILY Asteraceae

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21 (2006)

Helianthus decapetalus

SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 179-65-013:

Helianthus decapetalus   FAMILY Asteraceae

SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)

Helianthus decapetalus

INCLUDING Manual of the Southeastern Flora (Small, 1933, 1938)

Helianthus saxicola

 

COMMON NAME:
Thinleaf Sunflower, Forest Sunflower


         To see larger pictures, click or hover over the thumbnails.

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913    pnd_hede_001_lvd

        

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140809_372

August    Greenville County    SC

Swamp Rabbit Trail

The tips of its leaf blades are unusually long and slender, per www.illinoiswildflowers.info.

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140809_373

August    Greenville County    SC

Swamp Rabbit Trail

Leaf base widely cuneate or truncate, petioles oft obscured by decurrent blade, per Vascular Flora of the Carolinas (Radford, Ahles, & Bell, 1968).

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140809_374b

August    Greenville County    SC

Swamp Rabbit Trail

Longer phyllaries usually exceeding disk by half their length+, apex acuminate, per Weakley's Flora.


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

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140809_379

August    Greenville County    SC

Swamp Rabbit Trail

The disk is small compared to the rays, which may be 1.5" long, per Wildflowers of the Southern Mountains (Smith, 1998).

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140823_022

August    Greenville County    SC

Swamp Rabbit Trail

Ray florets 8-12; disc florets lobes yellow; anthers ~ dark brown to black, per Flora of North America.

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140823_025

August    Greenville County    SC

Swamp Rabbit Trail

The floral bracts are unusually long and slender, per www.illinoiswildflowers.info.

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140823_027

August    Greenville County    SC

Swamp Rabbit Trail

Leaf abaxial faces ± scabro-hispidulous, relatively sparsely gland-dotted, per Flora of North America.

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm140823_029

August    Greenville County    SC

Swamp Rabbit Trail

Upper stems have short bristly hairs; lower glabrous, sometimes glaucous, per www.illinoiswildflowers.info.

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

Keith Bradley    kab_h_decapetalus_2895

August    Macon County    NC

Nantahala National Forest

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm170914_0447

September    Haywood County    NC

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm170914_0450

September    Haywood County    NC

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm170914_0452

September    Haywood County    NC

image of Helianthus decapetalus, Thinleaf Sunflower, Forest Sunflower

JK Marlow    jkm121024_667

October    Cherokee County    NC

Murphy River Walk

Intergrades with H. strumosus, particularly in the southern Appalachians, per Flora of North America.

 

 

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Helianthus decapetalus   FAMILY Asteraceae

SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Helianthus decapetalus   FAMILY Asteraceae

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21
Helianthus decapetalus

SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 179-65-013:
Helianthus decapetalus   FAMILY Asteraceae

SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus decapetalus

INCLUDING Manual of the Southeastern Flora (Small, 1933, 1938)
Helianthus saxicola

 

Find by SCIENTIFIC NAME:

646

Forb
Perennial

Habitat: Mesic woodlands and forests, oak savannas, per Weakley's Flora

Native to the Carolinas & Georgia

Common (uncommon in GA Mountains, rare in GA Piedmont, rare in Coastal Plain)

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

LEAVES:
Simple
Opposite, or the upper alternate

FLOWER:
Summer/Fall
Rays: Yellow
Disc: Yellow
Inferior ovary
Disc flowers bisexual & fertile/ Ray flowers pistillate but sterile

FRUIT:
Summer/Fall
Brown
Achene

 

TO LEARN MORE about this plant, look it up in a good book!



 


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