Summary description from Wikipedia:

Helianthus giganteus in languages:

Czech

slunečnice obrovská

English

giant sunflower

Finnish

roima-auringonkukka

German

Riesen-Sonnenblume

Russian

Подсолнечник гигантский

Swedish

goliatsolros

Images from inaturalist.org observations:

We recommend you sign up for this excellent, free service.

©frees040, some rights reserved (CC-BY-NC)

©Morgan Rodenborg, some rights reserved (CC-BY-NC)

©Howard Williams, some rights reserved (CC-BY-SA)

©Howard Williams, some rights reserved (CC-BY-SA)

©Howard Williams, some rights reserved (CC-BY-SA)

©Howard Williams, some rights reserved (CC-BY-SA)

©Jen Peck, some rights reserved (CC-BY-NC)

©Jen Peck, some rights reserved (CC-BY-NC)

©cdiaz61, some rights reserved (CC-BY-NC)

©gwt2102, some rights reserved (CC-BY-NC)

©bstubbs, some rights reserved (CC-BY-NC)

©bstubbs, some rights reserved (CC-BY-NC)

©Tara Rose Littlefield, some rights reserved (CC-BY-NC)

©Tara Rose Littlefield, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©andysuk208, some rights reserved (CC-BY-NC)

©asper, some rights reserved (CC-BY-NC)

©SLKENNEDY, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Jacqueline Weber, some rights reserved (CC-BY-NC)

©Jacqueline Weber, some rights reserved (CC-BY-NC)

©Emma, some rights reserved (CC-BY-NC)

©Don Henise, some rights reserved (CC-BY-NC)

©rbbnature, some rights reserved (CC-BY-NC)

©rbbnature, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Julie Stella, some rights reserved (CC-BY-NC)

©Julie Stella, some rights reserved (CC-BY-NC)

©Laurier Green Team, some rights reserved (CC-BY-NC)

©Laurier Green Team, some rights reserved (CC-BY-NC)

©Laurier Green Team, some rights reserved (CC-BY-NC)

©Laurier Green Team, some rights reserved (CC-BY-NC)

©Laurier Green Team, some rights reserved (CC-BY-NC)

©Laurier Green Team, some rights reserved (CC-BY-NC)

©terrymcb, some rights reserved (CC-BY-NC)

©terrymcb, some rights reserved (CC-BY-NC)

©oliviakoval, some rights reserved (CC-BY-NC)

©oliviakoval, some rights reserved (CC-BY-NC)

©oliviakoval, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©mia_kamani, some rights reserved (CC-BY-NC)

©Rick Gray, some rights reserved (CC-BY-NC)

©Rick Gray, some rights reserved (CC-BY-NC)

©Rick Gray, some rights reserved (CC-BY-NC)

©Rick Gray, some rights reserved (CC-BY-NC)

©Tiffany, some rights reserved (CC0)

©Ryne Rutherford, some rights reserved (CC-BY-NC)

©Ryne Rutherford, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©tetwellcwf, some rights reserved (CC-BY-NC)

©Justine, some rights reserved (CC-BY-NC)

©Justine, some rights reserved (CC-BY-NC)

©pcornett, some rights reserved (CC-BY-NC)

©Jeanine Farley, some rights reserved (CC-BY-NC)

©paul mckinney, some rights reserved (CC-BY-NC)

©Chris Chaapel, some rights reserved (CC-BY-NC)

©Chris Chaapel, some rights reserved (CC-BY-NC)

©Chris Chaapel, some rights reserved (CC-BY-NC)

©Chris Chaapel, some rights reserved (CC-BY-NC)

©sallyk58, some rights reserved (CC-BY-NC)

©billharms56, some rights reserved (CC-BY-NC)

©Dave Woehr, some rights reserved (CC-BY-NC)

©veralind15, some rights reserved (CC-BY-NC)

©riversandroads, some rights reserved (CC-BY-NC)

©Anthony Zammit, some rights reserved (CC-BY-NC)

©rayrob, some rights reserved (CC-BY-NC)

©rayrob, some rights reserved (CC-BY-NC)

©rayrob, some rights reserved (CC-BY-NC)

©jasondavis48108, some rights reserved (CC-BY-NC)

©fieldwork427, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Randy Bodkins, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©Bill stitt, some rights reserved (CC-BY-NC)

©kja1188, some rights reserved (CC-BY-NC)

©Sarah Towler, some rights reserved (CC-BY-NC)

©calvertm, some rights reserved (CC-BY-NC)

©calvertm, some rights reserved (CC-BY-NC)

©rayrob, some rights reserved (CC-BY-NC)

©ptychobranchus, some rights reserved (CC-BY-NC)

©Paul McAfee, some rights reserved (CC-BY-NC)

©Paul McAfee, some rights reserved (CC-BY-NC)

©Paul McAfee, some rights reserved (CC-BY-NC)

©Paul McAfee, some rights reserved (CC-BY-NC)

©dnelesen, some rights reserved (CC-BY-NC)

©dnelesen, some rights reserved (CC-BY-NC)

©dsmith8686, some rights reserved (CC-BY-NC)

©cebrown00, some rights reserved (CC-BY-NC)

©cebrown00, some rights reserved (CC-BY-NC)

©cebrown00, some rights reserved (CC-BY-NC)

©cebrown00, some rights reserved (CC-BY-NC)

©Derek Slater, some rights reserved (CC-BY-NC)

©Michael Kielb, some rights reserved (CC-BY-NC)

©cbsmouse, some rights reserved (CC-BY-NC)

©ceegeecee, some rights reserved (CC-BY-NC)

©Nelson DeBarros, some rights reserved (CC-BY-NC)

©mollymoore50, some rights reserved (CC-BY-NC)

©Nikita Miller, some rights reserved (CC-BY-NC)

©monmouthnative, some rights reserved (CC-BY-NC)

©monmouthnative, some rights reserved (CC-BY-NC)

©monmouthnative, some rights reserved (CC-BY-NC)

©monmouthnative, some rights reserved (CC-BY-NC)

©monmouthnative, some rights reserved (CC-BY-NC)

©Fred Losi, some rights reserved (CC-BY-NC-SA)

©Fred Losi, some rights reserved (CC-BY-NC-SA)

©Fred Losi, some rights reserved (CC-BY-NC-SA)

©Ken Potter, some rights reserved (CC-BY-NC)

©JMYoungs, some rights reserved (CC-BY-NC)

©Paul Hotson, some rights reserved (CC-BY-NC)

©plantmandrew, some rights reserved (CC-BY-NC)

©kja1188, some rights reserved (CC-BY-NC)

©starrbright651, some rights reserved (CC-BY-NC)

©starrbright651, some rights reserved (CC-BY-NC)

©bgreenawalt, some rights reserved (CC-BY-NC)

©bugsmom94, some rights reserved (CC-BY-NC)

©degregorio, some rights reserved (CC-BY-NC)

©Alejandro Lopez, some rights reserved (CC-BY-NC-SA)

©bdubskis, some rights reserved (CC-BY-NC)

©dstein910, some rights reserved (CC-BY-NC)

©dstein910, some rights reserved (CC-BY-NC)

©racheljward, some rights reserved (CC-BY-NC)

©racheljward, some rights reserved (CC-BY-NC)

©aberquist, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©Ken Potter, some rights reserved (CC-BY-NC)

©aberquist, some rights reserved (CC-BY-NC)

©A.L., some rights reserved (CC-BY-NC)

©A.L., some rights reserved (CC-BY-NC)

Parent Taxon

• Helianthus

Sibling Taxa

• Helianthus agrestis
• Helianthus angustifolius
• Helianthus annuus
• Helianthus anomalus
• Helianthus argophyllus
• Helianthus arizonensis
• Helianthus atrorubens
• Helianthus bolanderi
• Helianthus californicus
• Helianthus carnosus
• Helianthus ciliaris
• Helianthus couplandii
• Helianthus cusickii
• Helianthus debilis
• Helianthus decapetalus
• Helianthus deserticola
• Helianthus devernii
• Helianthus dissectifolius
• Helianthus divaricatus
• Helianthus eggertii
• Helianthus exilis
• Helianthus floridanus
• Helianthus giganteus
• Helianthus glaucophyllus
• Helianthus gracilentus
• Helianthus grosseserratus
• Helianthus heterophyllus
• Helianthus hirsutus
• Helianthus inexpectatus
• Helianthus laciniatus
• Helianthus laevigatus
• Helianthus longifolius
• Helianthus maximiliani
• Helianthus microcephalus
• Helianthus mollis
• Helianthus mollissimus
• Helianthus multiflorus
• Helianthus navarri
• Helianthus neglectus
• Helianthus niveus
• Helianthus nuttallii
• Helianthus occidentalis
• Helianthus paradoxus
• Helianthus pauciflorus
• Helianthus petiolaris
• Helianthus porteri
• Helianthus praecox
• Helianthus praetermissus
• Helianthus pumilus
• Helianthus radula
• Helianthus resinosus
• Helianthus salicifolius
• Helianthus schweinitzii
• Helianthus silphioides
• Helianthus simulans
• Helianthus smithii
• Helianthus speciosus
• Helianthus strumosus
• Helianthus tuberosus
• Helianthus verticillatus
• Helianthus winteri
• Helianthus × alexidis
• Helianthus × ambiguus
• Helianthus × brevifolius
• Helianthus × cinereus
• Helianthus × divariserratus
• Helianthus × doronicoides
• Helianthus × glaucus
• Helianthus × intermedius
• Helianthus × kellermanii
• Helianthus × laetiflorus
• Helianthus × luxurians
• Helianthus × multiflorus

Top Observation Places

• Bethesda
• London
• Middletown
• Toronto
• Markham
• Willowdale
• Woburn
• Willowdale East
• Madison
• Burlington
• Ann Arbor