Minnesota Wildflowers


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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
USDA PLANTS database:Minnesota county distribution map
Spotted in Ramsey County at:

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Detailed Information

Flower: 7+petals

[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 near the base of a bract.

Leaves and stem: alternate opposite 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 stem 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 main stem is hairless and green or purplish with a white bloom like seen on a plum (see more photos below).

Notes:

Sawtooth Sunflower is similar to Giant Sunflower and Maximilian Sunflower. Giant Sunflower has a distinctly hairy stem and little or no stem on the leaves. Sawtooth Sunflower has a hairless main stem with longer leaf stems. Maximilian Sunflower has leaves that also fold up and arc, but they are mostly toothless with shorter leaf stems. In the location where these photos were taken, a number of plants had galls of various sizes on the stems at leaf joints (see leaf photo above, and photo below). One reference mentions that a species of weevil is a possible resident.

Where to buy native seed and plants

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

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

Map of native plant purveyors in the upper midwest

More photos

Photos taken at Rice Creek Trail Corridor, Shoreview, MN, August, 2009

Comments

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