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Helianthus giganteus Linnaeus. Tuberous Sunflower, Swamp Sunflower. Phen: Late Jul-Oct. Hab: Roadsides, woodland edges, bog edges, moist thickets, ditches. Dist: NB and ME west to MN, south to n. SC, n. GA, e. and c. TN, c. KY, n. IN, n. IL, and WI.

Origin/Endemic status: Native

Synonymy ⓘ: = C, F, FNA21, G, GW2, Il, K1, K3, K4, Mi, NE, NY, Oh3, Pa, RAB, S, SE1, Tat, Tn, Va, W, WV; > Helianthus alienus E.Watson – S; > Helianthus giganteus L. – S; > Helianthus validus E.Watson – S

Links to other floras: = Helianthus giganteus - FNA21

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Wetland Indicator Status:

  • Atlantic and Gulf Coastal Plain: FACW
  • Eastern Mountains and Piedmont: FACW
  • Great Plains: FAC
  • Midwest: FACW
  • Northcentral & Northeast: FACW

Heliophily ⓘ: 8

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image of plant© Gary P. Fleming | Original Image ⭷
image of plant© Erin Faulkner, some rights reserved (CC BY-NC), uploaded by Erin Faulkner source CC-BY-NC, permission granted to NCBG | Original Image ⭷
image of plant© Gary P. Fleming | Original Image ⭷
image of plant© Evan M. Raskin, some rights reserved (CC BY), uploaded by Evan M. Raskin source CC-BY | Original Image ⭷
image of plant© Evan M. Raskin, some rights reserved (CC BY), uploaded by Evan M. Raskin source CC-BY | Original Image ⭷
image of plant© Evan M. Raskin, some rights reserved (CC BY), uploaded by Evan M. Raskin source CC-BY | Original Image ⭷
image of plant© Evan M. Raskin, some rights reserved (CC BY), uploaded by Evan M. Raskin source CC-BY | Original Image ⭷
image of plant© Evan M. Raskin, some rights reserved (CC BY), uploaded by Evan M. Raskin source CC-BY | Original Image ⭷
image of plant© Erik Danielson source | Original Image ⭷
image of plant© Gary P. Fleming | Original Image ⭷
image of plant© Richard & Teresa Ware CC-BY-NC, permission granted to NCBG | Original Image ⭷
image of plant© Andrew Lane Gibson, some rights reserved (CC BY-NC), uploaded by Andrew Lane Gibson source CC-BY-NC, permission granted to NCBG | Original Image ⭷

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Horticultural Information

NCBG trait

Intro: Erect, rhizomatous perennial of bog edges, moist thickets and ditches.

Stems: Stems branching in upper 1/3, green or reddish-purple, rough-hairy.

Leaves: Leaves mostly alternate, petiolate, lance-shaped, 2-8 in. long, pinnately veined, with toothed or nearly smooth margins, rough-hairy above and soft-hairy beneath.

Inforescence:

Flowers: Composite flowers (heads) several in loose clusters; heads 2-3 in. wide, consisting of 10-20 yellow ray florets encircling a center disk of darker yellow tubular florets. Spreading and overlapping hairy, long, narrow bracts surround the base of each head.

Fruits: Fruit a blackish or mottled-brown, flattened, oblong achene.

Comments:

Height: 2-10 ft. (occasionally up to 13 ft.)

plant sale text:

bloom table text:

description: Erect, rhizomatous perennial of bog edges, moist thickets and ditches.

stems: Stems branching in upper 1/3, green or reddish-purple, rough-hairy.

leaves: Leaves mostly alternate, petiolate, lance-shaped, 2-8 in. long, pinnately veined, with toothed or nearly smooth margins, rough-hairy above and soft-hairy beneath.

inflorescence:

flowers: Composite flowers (heads) several in loose clusters; heads 2-3 in. wide, consisting of 10-20 yellow ray florets encircling a center disk of darker yellow tubular florets. Spreading and overlapping hairy, long, narrow bracts surround the base of each head.

fruits: Fruit a blackish or mottled-brown, flattened, oblong achene.

comments:

cultural notes:

germination code:

native range: