Not many growing things can live on rocks. Most plants need the
stability and nourishment that soil provides their roots. Insects and other
creatures can move around in search of what they need. But lichens, like the
Vulpicina pinastri shown here, don't hunt for their food. And they don't
have roots to draw nutrients from the soil. They often just hunker down and
spread across the hard, impenetrable surface of rocks.
But lichens are more than lowly rock
dwellers. They're like tiny chemical factories that make all kinds of
substances with interesting properties. Agricultural Research Service (ARS)
scientists are studying one such substance-- usnic acid-- that could mean big
trouble for pesky weeds.
Not many growing things can live on rocks. Most plants need the
stability and nourishment that soil provides their roots. Insects and other
creatures can move around in search of what they need. But lichens, like the
Vulpicina pinastri shown here, don't hunt for their food. And they don't
have roots to draw nutrients from the soil. They often just hunker down and
spread across the hard, impenetrable surface of rocks.
