One of our students defended her master's thesis today, and it was a very impressive study designed to see if a plant parasite responds to a host plant under water stress like insect herbivores would respond. The parasite is an amazing organism, dodder, a fully parasitic vine in the morning glory family. It looks like yellow-gold silly string, and it can make some really impressive infestations. One of the hardest problems is keeping a single parasite on a single host, and in nature the vine can sprawl across numerous hosts and make hundreds of connections to the vascular tissues of the host plants. It turns out that dodder doesn't react like aphids or other herbivous insects, but it is a totally amazing organism none-the-less. Image courtesy of Silvae.