Flora Fact: Frostweed and Monarchs
This native plant is an important pit stop for butterflies’ fall travel.
By Karen H. Clary
One weekend in late October, we ventured out to Colorado Bend State Park to camp. Halloween was just a few days away, so we carved some pumpkins we had brought along. When night fell, we set them out on the picnic table and lit the candles inside. It was a moonless night, and everyone marveled at how brightly they glowed in the dark.
Late afternoon the next day, we set out to find Spicewood Springs, a short walk downriver from the campground. As the trail dipped down into the shade of tall pecans, we walked straight into a cloud of monarch butterflies. Luckily for us, our Halloween outing coincided with the peak migration of monarchs making their way south to Mexico.
Out came the camera, and I set off to get the perfect monarch photo. I parked myself by a waist-high frostweed plant (Verbesina virginica L., a member of the sunflower family) in full bloom, covered with monarchs. I noticed that the monarchs were flocking to the white flower heads on all of the frostweed plants, busily probing the flowers for nectar.
Monarch butterflies follow the Colorado and other Texas rivers as they migrate to their wintering grounds in the highlands of northern Mexico. The fall migration takes about two months, and as they go, the monarchs drop down into the shelter of forests along the way to feed on flowers and rest overnight. They rest hanging from the branches of frostweeds and other plants.
Watching the monarchs at work, I was reminded of the importance of timing for both plants and butterflies. What would happen if the frostweeds bloomed too early or too late? Would the monarchs have enough fuel to make it to Mexico? Would the frostweeds get pollinated and set seed for next year?
Frostweed is a native plant found in shaded forests throughout the eastern half of the state. It spreads by underground stems, sprouts new plants in late spring and dies back in the winter. Although larger in size than most wildflowers, frostweed is hardly noticeable until it blooms in the fall. The plants produce long, green, ribbon-like wings that run the length of the stem. This characteristic makes them easy to identify when they aren’t in flower.
Frostweed gets its name from the plant’s ability to squeeze water from the stem when it freezes in winter. As water is squeezed out, it forms ribbons of ice crystals that take on fascinating shapes.
Frostweed has other names, including iceplant, white crownbeard, Indian tobacco and squawweed. Native Americans — including the Choctaw, Chickasaw, Creek and Mikasuki Seminole — used the leaves to treat fever, chills and body aches, and they used the roots as a purgative to treat indigestion.
Matt Turner, in Remarkable Plants of Texas, attributes the name “squawweed” to a specific use for women. Turner notes that the Kickapoo, as late as the 1970s, were still using hot decoctions of the plant for near-term and post-partum issues, such as cleansing the womb and stanching excessive bleeding.
You may be wondering if I ever did get that perfect monarch photo. Not even close! I think it’s time to make another trip out to Colorado Bend State Park to try again.