It carries a parasite of Monarch Butterflies identified as Ophryocystis elektroscirrha, or OE, which might induce defects inside the wings of Monarchs. As it doesn’t die back and may bloom late, the plant by itself may confuse Monarchs by signaling a breeding year when it’s time to migrate. Some links https://what-are-milkweed-plants89887.blogscribble.com/30979305/the-greatest-guide-to-is-milkweed-an-annual-or-perennial