Robert W. Freckmann Herbarium


  Helianthus giganteus L. image
Photographer: Kenneth J. Sytsma           

Caroline A. Creevey

Kenneth J. Sytsma

Matthew L. Wagner

Matthew L. Wagner

Matthew L. Wagner

Matthew L. Wagner

Merel R. Black

Merel R. Black

Merel R. Black

Merel R. Black

Merel R. Black

Christopher Noll

Robert Bierman

Janice Stiefel

Janice Stiefel
Family Asteraceae
Helianthus giganteus L.
giant sunflower, swamp sunflower, tall sunflower
Helianthus: derived from two Greek words helios, "sun," and anthos, "flower," in reference to the sunflower's supposed tendency to always turn toward the sun
giganteus: very large, from Giganteus "of or belonging to the giants"
County distribution map- click for detailed distribution maps.
Detailed Distribution:
Town Range Maps
Google Dot Maps
Status: Native
Plant: erect, perennial, 3'-10' tall forb; stems usually with spreading hairs but sometimes hairless, often purplish
Flower: head 1 3/4"- 3 1/4" wide with 10-20 yellow rays, yellow disks, hairy bracts (phyllaries) long and loose; inflorescence in loose clusters of several to many heads on stalks less than 4" long; blooms July-Oct.
Leaf:opposite on the lower stem, upper alternate, flat, narrow, at least 3 times as long as wide, upper surface rough, lower with long hairsleaf drawing
Habitat: moist; forests, swamps
Notes: very similar to H. grosseserratus except for longer hairs on underside of leaf, and rougher upper side.
(Glossary)

More Information Natural Communities Herbarium Specimens
All Helianthus list Google- Images or Text

Flora of North America (off site)
Synonyms 
Helianthus alienus E.Watson
Helianthus borealis E.Watson
Helianthus exasperatus E.Watson
Helianthus giganteus L. subsp. alienus (E.Watson) R.W.Long
Helianthus giganteus L. var. subtuberosus Britton
Helianthus membranaceus E.Watson
Helianthus nuttallii Torr. & A.Gray var. subtuberosus (Britton) B.Boivin
Helianthus subtuberosus (Britton) Britton
Helianthus validus E.Watson

         
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