I think we have to go back and look at the backs of the flowers where you can see the petals appear to narrow for some distance towards the base, they don't do that on Viguiera dentata.
http://swbiodiversity.org/sein...
Check the flowers on Bidens torta, the leaves don't match but could this be a hybrid garden escapee or a species of Bidens?
http://en.hortipedia.com/wiki/...
Check the flowers and seeds forming on the small photo ..
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