greater celandine

greater celandine (Chelidonium majus)
non-native, semi-invasive
photo taken in may

this plant is not considered officially invasive in massachusetts, but it is in nearby new hampshire and is colloquially called "invasive" due to its aggressive spreading and tendency to outcompete other plants.
like many weeds/invasives, greater celandine will grow anywhere; by the side of the road, in disturbed and nutrient-poor soil, etc. it prefers the shade. it has yellow-orange sap which irritates the skin, and the whole plant is mildly toxic. the audobon guide says it's specifically poisonous to chickens.
apparently because it's nasty sap looks kind of like bile, it was used in "four humors" style medicine to treat some illnesses! also freckles and warts, for some reason. the warts fact is great, because it means that (along with a bunch of other plants) greater celandine could also be called.... wartwort. heehee.
amusingly, greater celandine is not related to "lesser celandine" particularly closely - they're in different families. lesser is in the buttercup family and greater is in the poppy family.

greater celandine blooms throughout spring and summer.