I am trying to identify this milkweed that is loaded with Monarch larva. At first I thought it was Common milkweed, but I found a picture I took last year of the seed pod (sorry its out of focus), which shows that it doesn't have the soft spikes associated with Common. Also the flower color seems lighter than Common. Any help is appreciated!
I couldn't find anything else that resembled the plant pictured in a quick search save for Asclepias syriaca or Common milkweed. Here is the list that the USDA Plants page has for your area. The only other species that had the extreme knobby appearance of the seedpod was Asclepias speciosa and it has decidedly different flower. There are many species of milkweed however and it could have been planted from a wildflower seed mix I suppose, or I could have overlooked something in my search. Harry
