Milkweed is important because it's the only plant that is a host plant for Monarch butterflies. The butterflies lay their eggs, which look like tiny pearls, on the milkweed leaves.
When the caterpillar hatches out of the egg, it starts eating—and eating and eating! When it grows to be full size (about 2 inches), it is ready to turn into a chrysalis.
The changes that happen inside a chrysalis are like magic. "It's like a mouse turning into a hummingbird," says monarch scientist Dr. Lincoln Brower.
The butterfly emerges from the chrysalis after about 8-16 days.
You may not find any evidence of monarchs today, there haven't been many this summer, which is too bad. But now you know what milkweed looks like, and why it's an important host plant.
Look around for other butterflies, too!