This early spring blooming perennial is found across the Piedmont in Maryland, with scattered occurrences in the Coastal Plain and Allegheny Plateau, yet I had never seen it before this June. I have seen a lot of its look-alike cousin, Ranunculus ficaria, one of our worst alien invasive plants.
You may be wondering, if it’s an early spring bloomer, why did I see it in June?
I saw it in June because that’s when it blooms in Iceland.
Marsh marigold’s native range is widespread: it grows in wet areas across the Northern Hemisphere in temperate regions, including Canada and parts of the US (in the US it’s absent from the Deep South, southern Great Plains, Rocky Mountains, and the desert West). It’s endangered in Tennessee. It’s widespread in the lowlands in Iceland. There are three species of Caltha occuring in the US; worldwide there are about a dozen species.
This plant has been on my personal watch list for years, so on the one hand I was delighted to finally see it. On the other hand, I’m mildly annoyed that it was a few thousand miles from home.