I counted 9 in a site of about 50sqre meters along Clancy's track; I treated those west of the track by cutting off and spraying 1:100 glypho : water and I collected any of the broken-off seed heads that I could find and bagged them.
Barb I ran out of glypho mix yesterday but will do more cut and spray - I thought not to disturb the soil at this site as there are many weeds. Let's see how my cut-and-spray method works.... I haven't mapped with Field map. this is an area where you found ST before.