A few short days later, I stumbled across another perplexing milkweed mystery.
In June, a Florida gardener posted a mystery milkweed photo on my facebook page.
Over the 4th of July, I saw these same plants on a city boulevard in Chicago. After seeing them up close and personal, I was pretty sure they weren’t milkweed plants…but I left the windy city without making a positive ID.
Now, I’ve discovered a familiar ‘swampostor’ blending in to our swamp milkweed patch. But this time the faux milkweed made a fatal mistake. The flowing flowers clearly revealed its family secret…milkweed is not the father!

The leaves look like a cross between swamp milkweed and tropical milkweed, but with deeper veins. The stalks of the plants look more like tropical milkweed.

Dogbane is another plant that people often mistake for milkweed, but its leaves bear a closer resemblance to common milkweed.
Before I saw its flowers, I was wondering if this mystery plant could be the result of cross-pollination between swamp/tropical milkweed. After the blooms were revealed, I realized there was a milkweed impostor in our midst…
Milkweed Impostor 2
This July, a second milkweed impostor has been discovered in the swamp milkweed patch. It also has leaves resembling Asclepias incarnata, but its flowing purple panicles have revealed it as a milkweed brother from another mother:
This season I turned to a new ally in my question for plant identification:
Plant Identification Facebook Group
A helpful group member had my answer with a matter of minutes:
Lythrum salicaria (purple loosestrife)
After further research I discovered this plant is classified as a noxious weed in our state, so I dug it out and put it in the yard waste can.
Another milkweed mystery solved…
Click the following link to find 25+ REAL Milkweed Varieties for your butterfly garden.