I bought a green and white ground cover. The tag said it was Aegopodium podagraria ‘Variegatum’ or “Snow on the Mountain.” My horticulture book says A. podagraria is called Bishop’s Weed or Gout Weed and that Snow on the Mountain is called Euphorbia marginata. I’m confused – please clarify.

Common plant names are a constant source of confusion in the gardening industry. The plant Aegopodium podagraria ‘Variegatum’ has only one distinct botanical name. The confusion comes from the fact that it may have several common names such as those you listed. To make matters worse, the same common name may be given to several different plants throughout various parts of the country. With today’s demand for increased variety selection, you’re finding many more plants available with overlapping common names.

George Papadelis, from Telly’s Greenhouse in Troy, adds: the common name “Snow on the Mountain” refers to both Aegopodium podagraria ‘Variegatum’ and Euphorbia marginata. The Aegopodium is a perennial while the Euphorbia is an annual. Be careful with the Aegopodium, as it is very invasive and can be extremely difficult to get rid of. The annual Euphorbia may reseed itself from year to year, but invasiveness shouldn’t be a problem.