This parasitic plant eavesdrops on its host to know when to flower
A dodder plant begins its life looking like a tapeworm. The tiny plant, which will never grow leaves or roots, elongates in a spindly spiral. Round and round it swirls, searching for a host plant. When the dodder finds one, it latches on and infiltrates the host with tiny tubes that siphon off water and nutrients. The parasitic dodder grows, eventually covering its victim in a tangled, threadlike web of orange or yellow stems. Then, when the host plant flowers, so does the dodder, setting the stage for the sinister cycle to begin again. But that last part, reproduction, has remained a mystery. Normally, flowering plants use their leaves to sense when the environmental conditions are right to flower. So how does a parasitic plant with no leaves sense when to flower? By eavesdropping, a new study shows, using a chemical signal from the dodder’s host as its own. Australian dodder plants (Cuscuta...