Another Annoying Weed / Fleabane

We have been inundated with a newish weed, fleabane (Conya spp).
Originally from America, fleabane is usually found invading disturbed sites, bushland edges and roadsides and can tolerate poorly drained areas. But it’s in our pasture and wooded bush land.

There are seven fleabane species naturalised in Australia
Among these species, flaxleaf fleabane, tall fleabane and Canadian fleabane are the three most common, with flax leaf predominant.
They are annual herbs growing up to 2 m in height which form a rosettes first and then erect stems.
Leaves are generally soft, hairy and coarsely toothed with a single stemmed flower stalk with flowering heads. 

Flower heads are fluffy and white around 1 cm wide and seeds are achenes (a hard dry fruit containing a single seed) approximately 5 mm long with a tuft of fine hairs.

Flowers appear in summer followed quickly by seeds which are dispersed by wind and water run off.
Suggested control measures are bagging seed heads and removing them from site and pulling smaller plants or digging out tap root.
Both these are impractical on large properties.

We have resorted to spot spraying with good old glyphosate despite confirmed resistance of the weed to this herbicide.
‘Our’ weeds succumb in two to three days.

This process is a little tedious but good exercise.

Fleabane will reshoot and germinate after fire so follow up is required where seed may have been left in the soil.
This has been the cause of our (and many other properties) problem, even two years after the fires.
Am sure we will have to do more than one pass to get them all.