I don´t usually link to blogs until they have a bit of a track record but these sister blogs on Mexican ethnobotany could be really interesting. All come from Heike Vibrans who works at the main university for agriculture in Mexico.
Here’s one on Mexican (roughly) weeds, the volunteer plants that go along with cultivated plants. If you click through, you will find photos and plant identifications. Since the little books that I counted on for identifying plants in England or the US don’t exist here, this is really helpful.
And here’s a more general one on food, ethnobotany, etc. Interesting announcement of a conference on arthropods at the National University. And more photos of Mexican markets.
Also a list of organic markets in Mexico, a very useful resource (even though I think that pursuing organic as currently understood is a red herring).
Good luck with the blogs, Heike.