Minnesota Wildflowers


or try: advanced plant search
Share |

Helianthus giganteus (Giant Sunflower)

Plant Info
Also known as: Tall Sunflower, Swamp Sunflower
Genus:Helianthus
Family:Asteraceae (Aster)
Life cycle:perennial
Origin:native
Habitat:sun; moist woods, marshes, swamps
Bloom season:July - September
Plant height:4 to 10 feet
USDA PLANTS database:Minnesota county distribution map
Spotted in Ramsey County at:

Pick an image for a larger view. Most image enlargements are 50-100KB, though some may be larger. See the glossary for icon descriptions.

Detailed Information

Flower: 7+petals

[photo of flower] Flowers are about 2 to 3 inches across, 10 to 20 petals (ray flowers). The petals are bright to golden yellow; the center is a darker yellow. There are several to many flowers branching off at the top of the plant, each at the end of a stalk less than 4 inches long.

[photo of bracts] The bracts are long, narrow, loose and hairy.

Leaves and stem: alternate opposite simple

[photo of leaves] Leaves are up to 7 inches long and 2 inches wide, with little or no leaf stem. The texture of the upper side is very rough but the underside is more softly hairy. The edges are finely to coarsly toothed. Attachment is mostly alternate, but the lower leaves may be oppositely attached. The main stem is thick, hairy, and usually reddish or purple.

Notes:

Giant Sunflower and Sawtooth Sunflower are very similar. Sawtooth Sunflower has a smooth stem that has a white tint, whereas Giant Sunflower has a hairy red stem and hairier leaves. Jerusalem Artichoke is another tall sunflower, but has wider bracts and wider, more finely toothed leaves.

Where to buy native seed and plants

Help support this site by buying seeds & plants from these vendors. Tell them we sent you!

  • Shop for native seeds and plants at PrairieMoon.com!
  • Out Back Nursery and Landscaping - Where Ecology and Horticulture Unite
  • Shooting Star Native Seeds - Native Prairie Grass and Wildflower Seeds
  • Prairie Restorations - Bringing people together with the land

Map of native plant purveyors in the upper midwest

More photos

Photos taken at Pioneer Park, Blaine, MN, July-August 2008

Comments

Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Mike in Shoreview, between Lexington & Hodgson on Cty Road J
on: 2011-09-10 09:19:13

There is an artificial pond that was put in to replace wetlands taken for construction about 3/4 mile from Hodgson on CTY Rd J. They planted a full season of beautiful MN wildflowers to bloom every month. The Giant Sunflowers and Prairie Sunflowers are blooming now 9/10/2011.

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.



(required)




Note: Comments or information about plants outside of Minnesota may not be posted because I’d like to keep the focus of this web site on Minnesota. Thanks for your understanding.