Plantwatch: how baffling cheatgrass invaded the US west

Annual invasive plant spreads easily, is a fire menace and mysteriously grows well under streetlightsSomething odd has been appearing under streetlights in the American west. The ecologist Dr Shannon Murphy was walking her dog through an alley in Denver, Colorado, when she noticed clumps of invasive cheatgrass flourishing under streetlights. She was already growing prairie grasses in artificially lit greenhouses to study how moths interacted with the plants, but was surprised that cheatgrass thrived under the lights, while native grasses did not see any benefit.That inspired a team of researchers to survey Denver's alleys, and they found that cheatgrass was three times more likely to grow under streetlights than in unlit areas, or near utility poles without lights. How streetlights boosted the plant left the scientists baffled, although it could explain why cheatgrass is thriving in many other major urban areas. Continue reading...