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
Dig deeper at SERNEC, a consortium of southeastern herbaria.
Read more about Thinleaf Sunflower at Vascular Plants of North Carolina.
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.
)
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913 pnd_hede_001_lvd
)
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.
)
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).
)
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.
COMPARE
involucral bracts of Sunflowers
)
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).
)
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.
)
JK Marlow jkm140823_025
August Greenville County SC
Swamp Rabbit Trail
The floral bracts are unusually long and slender, per www.illinoiswildflowers.info.
)
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.
)
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.
)
Keith Bradley kab_h_decapetalus_2895
August Macon County NC
Nantahala National Forest
)
JK Marlow jkm170914_0447
September Haywood County NC
)
JK Marlow jkm170914_0450
September Haywood County NC
)
JK Marlow jkm170914_0452
September Haywood County NC
)
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
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)
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!
- Newcomb's Wildflower Guide (Newcomb, 1977) p388
- Wildflowers of the Atlantic Southeast (Cotterman, Waitt, & Weakley, 2019) p298
- Wildflowers of the Eastern United States (Duncan & Duncan, 1999) p124
- Field Guide to the Wildflowers of Georgia (Chafin, 2016) p088
- Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005) p351
- Wildflowers of the Southern Mountains (Smith, 1998) p192
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