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Manitoba Museum

Aster (Asteraceae)

Stiff Sunflower

Helianthus pauciflorus ssp. subrhomboideus (Rydb.) O. Spring & E.E. Schill.

This attractive perennial spreads by underground rhizomes, often forming colonies of plants. They are allelopathic, meaning that their roots produce chemicals that hinder the growth of nearby plants. Although their flowers are not fragrant, they are attractive to birds, butterflies, and bees. Their common name comes from the ability to move their flowering heads in the direction of the sun.

Flower Colour:

  • Yellow

Flowering Season:

  • Summer
  • Fall

Flowering Months:

  • August
  • September

Canadian Rarity Status:

Not rare. Listed as “may be at risk” in Ontario, and “exotic” in British Columbia, New Brunswick, Nova Scotia, and Prince Edward Island.

Physical Appearance:

The reddish stems (one to several) grow 30 –200 cm tall, and are branched where flowers occur. Lance to linear shaped leaves are opposite, hairy, and have three noticeable veins. Flowering heads (2-10) are up to 25 mm in diameter and occur in a loose cluster. They consist of 10-20 yellow ray florets and at least 75 reddish-brown disc florets. Behind each head is a whorl of pointed, egg shaped bracts. Fruits are achenes topped by two awns.

Similar Species:

Narrow-leaved Sunflower, Prairie Sunflower (Helianthus petiolaris Nutt.), Sneezeweed (Helenium autumnale L.)

Gardening Notes:

Seeds and/or plants are often available from greenhouses and seed supply companies specializing in native plants. Plants are a good addition to butterfly or prairie gardens.

Canadian Distribution:

  • Alberta
  • British Columbia
  • Manitoba
  • New Brunswick
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Saskatchewan
  • Yukon

Prairie Types:

  • Fescue Prairie
  • Tall Grass Prairie


  • Prairies

Moisture Conditions:

  • Dry
  • Moderate

Light Preference:

  • Full Sun

Soil Preference:

  • Clay
  • Sand
  • Silt
Stiff Sunflower