It carries a parasite of Monarch Butterflies named Ophryocystis elektroscirrha, or OE, which could bring about defects from the wings of Monarchs. As it doesn’t die back again and might bloom late, the plant by itself can also confuse Monarchs by signaling a breeding period when it’s time to migrate. https://hectorjszhm.theideasblog.com/31372379/an-unbiased-view-of-is-butterfly-milkweed-a-perennial