Flaxleaf Fleabane

Other Common Names: Wavy-leaf fleabane, Argentine fleabane, hairy horseweed, asthma weed and hairy fleabane. 

Synonyms: Conyza bonariensis​.

Reaches maturity within one year, with seeds remaining viable in the soil for up to one year. Fleabane plants can produce over 100 000 seeds each. Fire promotes rapid recruitment from the soil seed bank, often increasing seedling emergence after disturbance. Plants are typically growing between 0.15 to 1.5 m tall.

• Large plants are quite woody and have a deep taproot 

Can grow in a variety of soils. Grows in temperate and sub-tropical regions. Can grow under varying rainfall from moderate winter rainfall to summer rainfall. 

Similar non-native species: Similar to the ​tall fleabane (Erigonon sumatrensis) however can be distinguished by its taller main stem (up to 2m) and dark green colour compared to the flaxleaf. Also similar to the Canadian fleabane (Erigonon canadensis)​ which can be distinguished by its light yellow-green stem and smaller brown flowers compared to the flaxleafs whitish flowers.

Seeds are dispersed by wind, water and by sticking to animals and vehicles.

• Strongly suppresses neighbouring plants through allelopathy.
• Produces phenolic compounds (e.g. chlorogenic, caffeic acids) that inhibit plant growth.
• Reduces plant diversity and richness, often forming more simplified plant communities.
• Inhibits seed germination and seedling growth, especially root growth.
• Can reduce growth and survival of both native species and crops.
• Alters soil properties, including; increasing soil pH, increasing electrical conductivity and releases chemicals during decay that affect microbial activity.

​​Introduced into Australia as a contaminant of livestock in the 1840’s. First records in NSW, Victoria and South Australia, arrival into Western Australia is unknown​.