I noticed this flowering creeping perennial at the wildflower garden at the Museum of Natural History. I thought “how lovely” because I had no clue what it was, initially. Moneywort, as this turned out to be, is native to Europe, and was introduced in North America as a horticultural plant. It first got here in 1739. It has escaped from cultivation and spread extensively. Moneywort seeds were sold in the United States as early as 1833, and it was established outside cultivation in the United States by 1900. I am not sure if its presence at the garden was intentional or not, but there it is.
As a side note, non-natives frequently come along with plants bought from nurseries. They are sometimes grown side by side and seeds or seedlings can make it into the potting soil or pots respectively. At the same time, invasives are everywhere and they are equally free to disperse their seeds into the environment.
As for moneywort, it can be an agressive plant especially in wet and moist conditions. In some states it has been banned from being sold. It often wanders out of gardens into the woods, where its spread and impact is difficult to control and gauge.
Thanks to Ellen Todd, who alerted me to this, I want to explicitly state that since February of this year (2017) moneywort has been listed on the Massachusetts Prohibited Plant list. “The importation, sale, and trade of the plants listed below is banned. This ban also covers the purchase and distribution of these plants and related activities, and includes all cultivars, varieties and hybrids of the plants listed below.
I noticed moneywort in a display garden at the museum of Natural History in Brewster of all places, that is why it is on my list – my plant index only lists plants I have in my own woodland garden or plants I have observed somewhere nearby. There is an article attached to each, and in the case of moneywort I already mentioned that it was banned in some states. Thanks a million to Ellen for the heads-up on this status change once again. I appreciate others filling in the many gaps and misses on this blog- we’re all the wiser for it
To be fair to to Natural History museum, the plant was there in 2011 when I observed it and wrote the article. I have not been back to see if it is still part of their garden. They used to have a fairly active local garden club, so the plantings may have changed.