Flora Fact: The Seduction of Venus
Venus’ looking glass has shiny, mirror-like seeds to reflect its beauty.
By Jason Singhurst
Venus’ looking glass (Triodanis spp.), also known as clasping bellwort, has a seductive appearance that will easily draw your attention, requiring a closer look at this amazing spring annual wildflower. Early in my botanical career in Texas, I was puzzled about how this plant received its common name. I found that it was named for its very shiny seeds that have an appearance of a looking glass or tiny mirrors.
Venus’ looking glass mainly blooms from spring to early summer and grows in full sun, in mostly well-drained soils. It reproduces best in areas with sparse or low vegetation and are native to most of North America.
Texas is blessed with all seven species of Venus’ looking glass known in the United States. No matter what region of the state you live in, you will likely come across this showy member of the bluebell family (Campanulaceae). The most prolific Venus’ looking glass in Texas is the clasping Venus’ looking glass (Triodanis perfoliata), which can be found in a variety of Texas habitats including tallgrass prairies, post oak savannas, longleaf pine savannas, creek and river banks, South Texas caliche and sandstone uplands, and isolated locations in the Davis Mountains in West Texas.
Venus' looking glass.
Texas Venus’ looking glass (Triodanis texana) is endemic to Texas (meaning it’s found nowhere else but the Lone Star State), where its habitat is primarily restricted to savanna openings in deep sand soils in the central and southern post oak savanna (from Tyler southwest through Bryan/College Station to south of San Antonio). Plant lovers can observe Texas Venus’ looking glass at Bastrop, Lake Fairfield, Lake Somerville and Fort Boggy state parks and Gus Engeling Wildlife Management Area.
Venus’ looking glass is a taprooted annual that grows to heights of 6 to 30 inches. The leaves are up to one inch long, alternate, light green, hairy and heart-shaped with wavy or toothed margins, and they strongly clasp the stem. The stem and leaves contain a milky sap.
Flowers are solitary, with five petals and five sepals (leaflike parts), and range in color from blue or violet to white. The flowers on the lower stem are self-pollinated and never open, resembling little telescopes searching out the skies above. Flowers on the upper stem are wide-open and star-shaped. The flowers are tucked away in the axis of roundish, clasping, leaf-like bracts. Fruit is an elongated linear seed pod that releases many tiny, windblown seeds.
Invertebrate wildlife such as carpenter bees, green metallic bees and plasterer bees frequently visit the flowers. The plasterer bee is a specialist pollinator of Venus’ looking glass. Other insect visitors include small butterflies, bumblebees, skippers and flies. Some mammal herbivores consume this plant; however, it is not a significant food source.
When you are hiking about Texas’ landscapes this spring and early summer, look out for the telescope-appearing Venus’ looking glass flowers that are in search of pollinators and plant enthusiasts.