Common Milkweed
Asclepias syriaca

f25 @ 1/160s, ISO:2000, Nikon D3S w 105mm macro

"Asclepias syriaca," Wikipedia, the free encyclopedia. Monarch butterfly larvae consume only milkweeds, and monarch populations may decline when milkweeds are eliminated with herbicides. The development and widely adopted cultivation of herbicide-resistant staple crops such as corn and soybeans have led to a massive reduction in weeds and native plants such as milkweeds. Subsequently, this has played a significant part in the population decline of the monarch butterfly. In 2018 the CEO of the National Wildlife Federation stated that the population of the monarch butterfly is now down 90 percent in the last 20 years and cited the reduction in milkweed as a contributing factor.
Francis A. Crane Wildlife management Area, East Falmouth, Massachusetts