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Report an Invasive Species

Texas blueweed

Texas blueweed

Texas blueweed

(Helianthus ciliaris)

Priority: -  Prevent

Tags: Agricultural

Identification and Reproduction

Identification: 

  • Texas blueweed is a species of sunflower that grows from creeping rhizomes. 
  • Stems extend upright and range between 40 to 70 cm tall. 

  • Can appear clumpy, as numerous shoots will arise from the underground rhizomes. 
  • Leaves and stems are blue-green to grey-green in colour and narrowly lance-shaped.
  • Leaves attach directly to the stem, have wavy margins and stiff hairs. 
  • Blooms occur from June through October. Flowers are 2-4 cm wide, have yellow ray florets and reddish disk florets. 

(Richard Reynolds)

Reproduction: 

  • Texas blue can spread through rhizome fragments and seed production. 
  • Often rhizome are fragmented and transported by agricultural means.
  • Seed germination is slow and regarded as insignificant in local spread.  

Habitat & Ecology

  • It grows rapidly on recently disturbed sites, cultivated lands, ditches and roadsides. 
  • It has the most invasive characteristics on cultivated lands and does not appear to invade natural environments. 
  • Currently absent from Canada but distributed throughout the the southwest of US as it is native to Texas and Mexico. 

Impacts

Social: 

  • It is aggressive, forming extensive colonies where possible. 
  • Crop yields and qualities are reduced. 
  • Contaminates seed crops. 

Management

Prevention is a high priority for this plant. 

  • Use clean, high-quality seed mixtures that are certified. 
  • Ensure that equipment, vehicles and tools are clean and free of debris. 
  • Continously monitor cultivated sites for new infestations.
  • Planting of perennial grasses can prevent Texas blueweed establishment.   
  • Report this plant if you think you have seen it. 

Resources

For more for details check out the Invasive Species Compendium datasheet on Helianthus ciliaris (Texas blueweed). 

Header photo (J L Johnson).