Flora Fact: Barometer Bush
This hardy native blooms when the humidity shoots up.
By Sheryl Smith-Rodgers
One day last fall, weather forecasts predicted rain across the drought-stricken Texas Hill Country. On the horizon, storm clouds loomed. Sadly, not a single drop fell in our neighborhood. Humidity levels, though, must have soared because across the street stood a scraggly cenizo, covered with lavender blooms.
Both rain and moist air can trigger cenizo’s showy flowering. For that reason, Leucophyllum frutescens has been dubbed the barometer bush. But hold on — this hardy native with silvery-green leaves answers to other names, too: Texas sage, purple sage, Texas ranger, Texas silverleaf and senisa.
Cenizo — Spanish for "ash colored" — occurs in the rocky, limestone soils of northern Mexico, the Rio Grande Plains, Trans-Pecos region and western Edwards Plateau. Extremely drought and heat tolerant, the medium-sized shrub provides cover for wildlife and nest sites for birds. It’s also a caterpillar host plant for Calleta silkmoths and Theona checkerspots. Native Americans and early settlers once brewed a medicinal tea from cenizo leaves.
In 2005, state legislators designated Texas purple sage as the official state native shrub. (Crape myrtle — originally imported from China — was named state shrub in 1997.) A sage it is not, though. Leucophyllum frutescens belongs to the figwort family, which includes toadflax, wild snapdragon and Indian paintbrush.