Question
I need to identify a plant that I found in some pasture land and near some wetlands in the coastal region of the southern Mexican state of Oaxaca.  I will email a couple photos, although they are not too great.
The flower is yellow, and the plant height is about 1m for the larger plants.   
Or, if you could suggest an online identification key that would be helpful, I'd appreciate that as well.

Answer
So sorry for the delay.  We are just getting back from vacation and I have been swamped, both by the business and questions from AllExperts.  For this reason, my answers may be a little shorter than normal.  I hope you will understand.

An obscure plant such as that one, that is not known to the Horticultural industry is going to require live or dried specimens of flowers, plant, and seed for positive identification as well as a botanical key that covers the area down there if one exists.  None of which I have.

Sorry,


John