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Milkweeds are diverse and widespread. They are also well known because of putative medicinal properties and now, especially because of their association with Monarch Butterflies. Monarchs lay their eggs on milkweed and their caterpillars feed on milkweeds – consuming toxic chemicals, which they store in their body, making both the caterpillars and the adult butterflies toxic and noxious to would be predators. What is less well known is that Monarch butterfly populations are declining rapidly. Why? Excessive use of herbicides that kill milkweeds along with other plants, clearing of land for human uses, pesticides that kill insects, and climate change are all likely involved. Florida is home to at least 24 species of milkweeds and also to a sizeable, but perhaps shrinking, monarch butterfly population – a population that includes migrant monarchs that pass through Florida from more northern breeding areas to wintering areas in Mexico and other areas south of us. There is much we don’t know, but scientists are concerned and investigating the potential links.