91色情片

MEDICINAL plants don鈥檛 only lurk deep in primary rainforests. They鈥檙e just as
likely to be growing as weeds in roadside ditches and abandoned fields, an
ethnobotanist claims.

John R. Stepp at the University of Georgia in Athens surveyed 208 Highland
Maya people in six communities in Chiapas, Mexico. Rather than wander into the
rainforest when they needed medicine, he found they would often go to a nearby
ditch.

Stepp says the popular idea that the untouched rainforests are a treasure
trove of medicinal plants for indigenous people is wrong. 鈥淚f there are
medicinal plants in there, no one is using them,鈥� Stepp says.

Over a period of seven months, Stepp identified 103 plants the Chiapas Maya
used for medicine. His colleague Daniel E. Moerman at the University of Michigan
in Dearborn then compared these plants with a list of the region鈥檚 9000 known
plants. Although only 13 per cent of the known plants were weeds, about 34 per
cent of those the Maya used as medicines were weeds.

Why do the Maya choose so many weeds? Stepp says it鈥檚 partly because they are
common and close by: the plants tend to crop up in the ecologically disturbed
areas where the Maya live. Another factor may be that weeds have to compete
aggressively in disturbed environments, so they churn out chemicals that
discourage competitors and pests. These chemicals are 鈥渂ioactive鈥� and tend to
make good medicine.

Mark Plotkin, an ethnobotanist with the Smithsonian Institution, says Stepp鈥檚
results aren鈥檛 surprising in a 鈥渕osaic鈥� area such as Chiapas, which is made up
of forests and fields. 鈥淏ut I don鈥檛 think that calls into question the popular
assumption that there is a lot more to be found in the primary rainforest than
we already know.鈥�