Weeds in disturbed areas may be source of more medically important compounds than plants in tropical rainforests. ‘The idea that tropical rainforests may hold the key to new medicines that can solve everything from AIDS to cancer has been around for some
time. Indeed, one study found that of the 95 plant species now used for prescription drugs, 39 originate in and around tropical forests.

Stepp, however, began to ask a simple question during his doctoral field work in the Mexican state of Chiapas and research with North American
tribes: Why would indigenous people walk miles to find medicinal plants if the plants were available on a roadside a few houses down? Working
with the Maya in Chiapas, Stepp found that, in fact, nearly all the medically important plants being used grow as weeds in disturbed areas not
far from their houses or villages.

“What we found is that people use what they have nearby, except on rare occasions,” said Stepp.’ [Although it predated my interest in ethnopharmacology, I did fieldworkwith the Highland Maya in Chiapas in the early ’70’s myself.]