Feb. 13, 2019

common dodder, Cuscuta gronovii

Looking at morning-glory family plants that don't look the role inevitably leads to dodder. These little flowers are hardly an eighth inch across. Like so many of their relatives, they're vines. But they put that trait to a very different use. They're parasites, winding around and infesting many herbaceous hosts. The seeds germinate, and the shoots grope around for another sprouting herb. If they don't find one very quickly, they die. When they do find a victim, they grab hold and root. The base of the dodder dies, and they become completely dependent, even pendant, on the other plant. This one was on an aster. Some shoots die if the host is unaccepting. And I once saw some on arrowheads, which apparently can host dodder well enough for them to live, but not to flower and fruit. This dodder is indeed common, growing in every state and province except AK, CA, HI, NV, UT, WA, BC, LB, NF, NT, NU, and YT. Ives Fen Preserve, Lenawee Co MI, 9/16/11.