Fleabane (Conyza species)

Description

Fleabanes are annual herbs with a basal rosette of entire or toothed leaves and an erect, often greyish, leafy flowering stem. The small flower heads are cream to white and do not have the radiating petal-like florets seen in many daisies. Instead there are several slender tubular florets. Tiny fruits are topped by a ring of bristles.

Three species are likely to be found along the south coast and all are common weeds of roadsides and disturbed bushland. All flower in summer and autumn.

Tall Fleabane (Conyza sumatrensis was Conyza albida) may reach 2 m high, is usually unbranched below the inflorescence and has hairy leaves. It is native to North America. Flaxleaf Fleabane (Conyza bonariensis) is usually to 1 m high and usually branched with greyish hairy leaves.

It is from North America.

Fleabane (Conyza parva) has almost hairless leaves and smaller flower heads. It is native to South America.

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Control

Spray road shoulders with 2-3 L/ha glyphosate(450g/L) plus wetting agent in early summer to reduce the spread of seed in the slipstream of traffic. On other areas, apply 1 L/ha glyphosate(450g/L) after stem elongation and before flowering in late spring to summer each year when the plants are actively growing.

A mixture of 1 L glyphosate(450g/L) plus 2 L water can be used to wipe the stems of plants. Lontrel®750 at 200 g/ha or 4 g plus 25 mL wetting agent in 10 L water can be used for fairly selective control in bushland. Isolated patches can be sprayed with a mixture of 50 mL Tordon®75-D in 10 L water for control of plants and residual control of seedlings. For large, old infesations, split sprays using 2 L/ha glyphosate(450g/L) or 2 L/ha 2,4-D amine(625g/L) followed 3-7 days later by 2 L/ha paraquat(250g/L) has provided the best control.

Hand pulling after stem elongation is effective on loose soils, but on heavier soils a weed fork is required to prevent the plant breaking and regrowing from the base. Mowing is not effective. Planting perennial species to increase ground cover and shade will help reduce re-infestation. Continuous grazing usually gives adequate control