Helianthus grosseserratus (Sawtooth Sunflower)

Plant Info
Also known as:
Genus:Helianthus
Family:Asteraceae (Aster)
Life cycle:perennial
Origin:native
Habitat:sun; moist fields, prairies, ditches, roadsides
Bloom season:July - October
Plant height:2 to 10 feet
Wetland Indicator Status:GP: FACW MW: FACW NCNE: FACW
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: 7+petals Cluster type: panicle

[photo of flowers] Flowers are at the end of branching stems at the top of the plant. Individual flowers are 2½ to 4 inches across with 10 to 20 ray flowers (petals) and yellow center disk flowers.

[photo of bracts] There are a few layers of bracts behind the flower; bracts are narrow, sharply pointed and spreading with fine hairs around the edges especially near the base of a bract.

Leaves and stem: Leaf attachment: alternate Leaf attachment: opposite Leaf type: simple

[photo of leaves] Leaves are up to 8 inches long and 2½ inches wide, coarsely toothed, pointed at the tip, tapering at the base, on a stalk up to 1½ inches long. The texture is rough. Leaves are mostly oppositely attached but are alternate in the upper part of the plant; they tend to fold up along the center vein, and may be arching. The stem is hairless and green or purplish with a white bloom like seen on a plum (see more photos below).

Fruit: Fruit type: seed without plume

The center disk forms a head of dry seed each about 1/8 inch long and without a tuft of hair, but with 2 somewhat bristly scales at the top.

Notes:

Sawtooth Sunflower is similar to Giant Sunflower (Helianthus giganteus) and Maximilian Sunflower (Helianthus maximiliani). Giant Sunflower has a distinctly hairy stem and its leaves are stalkless or nearly so, whereas Sawtooth Sunflower has a hairless stem, often with a whitish bloom, and longer leaf stalks. Maximilian Sunflower has leaves that also fold up and arc like Sawtooth Sunflower, but they are mostly toothless with shorter stalks. In the location where many of these photos were taken, a number of plants had galls of various sizes on the stems near leaf joints (see leaf photo above, and photo below). One reference mentions that a species of weevil is a possible resident.

Please visit our sponsors

  • Wild Ones Twin Cities Chapter

Where to buy native seed and plants ↓

Map of native plant purveyors in the upper midwest

  • Natural Shore Technologies - Using science to improve land and water
  • Itasca Ladyslipper Farm - Native orchids, container grown
  • Prairie Restorations - Bringing people together with the land
  • Shop for native seeds and plants at PrairieMoon.com!
  • Shooting Star Native Seeds - Native Prairie Grass and Wildflower Seeds

More photos

Photos by K. Chayka taken at Rice Creek Trail Corridor, Ramsey County. Other photos courtesy Peter M. Dziuk.

Comments

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

Posted by: Jonya - Olmsted County
on: 2012-09-02 17:54:46

Is this what is in bloom all along the roadsides? From the pictures, this is the leaf, and other aspects of the plant match. The flowers of course look very much like other small sunflower-types. Thanks!

Posted by: Jill - Zimmerman
on: 2016-09-18 14:10:19

bloomed sept 17

Posted by: GERALD S - Highway US 53 Canyon mn and north
on: 2016-10-03 06:13:11

Where can I buy seeds for this plant?

Posted by: K. Chayka
on: 2016-10-03 15:56:34

Gerald, we do not track who sells what, but see "where to buy native seeds and plants" that is on most pages of this website. If none of those vendors carry it maybe one knows who does.

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 and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.