Why has ragweed – a highly allergenic plant – been spreading so quickly? A researcher took a six-week road trip across the USA and collected 1000 samples of the plant from roadsides and herbaria to answer that exact question.
Why has ragweed – a highly allergenic plant – been spreading so quickly? A researcher took a six-week road trip across the USA and collected 1000 samples of the plant from roadsides and herbaria to answer that exact question.