4 August 2022
By the end of July in western Pennsylvania, there are patches of orange string draped over plants in moist locations on the edge of the forest. The orange strings are dodder (Cuscata), a native annual parasitic vine that blooms from July to October.
Dodder wraps itself around its host and inserts tiny haustoria to suck out water and nutrients. Last week I found it parasitizing invasive porcelain berry — Go, dodder! — but dodder won’t beat back the grapevine. Dodder doesn’t kill its host.
Look very closely and you can the haustoria clinging and dodder’s tiny flowers that are pollinated by wasps.
Dodder will die at the end of the growing season yet you may find it in the same spot every year. Find out why this happens and other interesting tidbits in this vintage article.
(photos by Kate St. John and Esther Allen)