non-native, sometimes considered a weed
pictures taken in early may.
this flower is native to europe and considered invasive in some states, but not in massachusetts. it's an aggressive ground cover, spreading via stolons. (a stolon is a "runner" - a long stem that stretches out and grows roots.) bugleweed flowers bloom from may through june, and reportedly the flower "spikes" can get as tall as 14 inches! it grows in a wide range of shade levels, moisture levels, and temperatures. apparently it can even grow near black walnut trees, which exude chemicals that kill most other plants that try to grow near them!
butterflies seem to like the flowers in the UK - this site lists eighteen kinds that feed off it! it seems less popular with butterflies here, though bees and other pollinators seem to like it just fine.
my yard has a white bugleweed, which is interesting and i've never seen it before - apparently this is a human-produced cultivar of ajuga reptans, so maybe it was planted here intentionally at one point.
bugleweed blooms from early may to mid-june.