Flora Fact

Roadside Sunshine

Mexican hat’s more than just a highway highlight. 

by Rushton Skinner

All along the Texas asphalt, smatterings of red, yellow and blue remind drivers that summer is in full swing. Among the Indian blankets and paintbrushes, you can find Ratibida columnifera, or Mexican hat. Like many native species, the aptly named wildflower isn’t just a sight for sore eyes, it has a history of medicinal use as well. 

Mexican hat stands 2-3 feet tall and blooms until the end of Texas summer ... around November. The sombrero-shaped flower is a member of the Aster family, sharing a lineage with sunflowers, daisies and echinacea. Family members are more easily identified up close because of their unique inflorescence; Asters look like a single flower from a distance, but they’re actually a structure of many little flowers.

The “plunger” pollination system is how most members of the Aster family reproduce. In Mexican hat’s case, the cone portion atop the bright petals hosts dozens of tiny florets, the flowers within the flower. Each floret has male and female parts; as the female stigma extends through the male anther, pollen sacs rupture and are pushed out on the stigma. This facilitates cross-pollination while avoiding self-pollination.

The thimble-like top is bitter enough to deter most large mammals, partly due to the minuscule, chemical-secreting hairs called trichomes that also repel smaller six-legged thieves from immature pollen. Livestock, however, enjoy the plant in its early stages of growth, while birds and smaller mammals enjoy its seeds.

Mexican hat most likely originated in the plains of the Midwest but has since been naturalized around North America. Early people had a use for each part of the plant. The leaves and stem helped fight infection, snakebite and poison ivy. The conical top was and is used as bitters to fight headaches and stomachaches. Today, herbalists use the root as a replacement for (or in conjunction with) Valerian root, a soporific that encourages sleep.