Giant/Tall Sunflower (Helianthus giganteus) 2006-9-16 Cape May, NJ

native
found in open areas in moist soil, wet meadows, swamps
flowers late summer to fall
stems usually reddish and hairy
leaves mostly alternate
12-20 petals (number varies depending on source)
color yellow to pale yellow

Flora of North America:
Helianthus giganteus "is distinctive in its hairy, reddish-colored stems, dark anther appendages, and prominent setae on the petioles"
full scientific description at Flora of North America:
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066882
common language description:
http://www.illinoiswildflowers.info/wetland/plants/gnt_sunflower.html

details:
http://www.tropicos.org/Name/2702636
dried specimen:
http://www.tropicos.org/Image/100129641
synonyms:
Helianthus alienus
Helianthus validus
Common Names:
giant sunflower
swamp sunflower
tall sunflower

CalPhotos:
http://calphotos.berkeley.edu/cgi/img_query?where-lifeform=any&rel-taxon=contains&where-taxon=Helianthus+giganteus&rel-namesoup=matchphrase&where-namesoup=&rel-location=matchphrase&where-location=&rel-county=eq&where-county=any&rel-state=eq&where-state=any&rel-country=eq&where-country=any&where-collectn=any&rel-photographer=contains&where-photographer=&rel-kwid=equals&where-kwid=&max_rows=120

accepted name:
https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=36612

other sites:
http://plants.usda.gov/core/profile?symbol=HEGI
http://www.illinoiswildflowers.info/wetland/plants/gnt_sunflower.html
https://www.minnesotawildflowers.info/flower/giant-sunflower
http://www.ct-botanical-society.org/Plants/view/251
http://www.southeasternflora.com/view_flora.php?plantid=936
http://capemaywildlife.com/_templates/group_sunflowers.html#Swamp%20Sunflower
http://www.wildflower.org/plants/result.php?id_plant=HEGI