A Botanical Twofer

Every so often nature presents a teaser that just won’t stop tickling the imagination. An ongoing tickler for me has been a plant that I often encounter in the desert’s dry, sandy washes or on exposed mountain slopes. It’s called desert trumpet (Eriogonum inflatum). 

Desert trumpet isn’t a show-stopper. It features a bouquet of woody green stems that sprout from a rosette of small leaves at its base. Its yellow blooms are so tiny that you need a magnifying lens to see them. You might easily walk right past the plant if it weren’t for a distinctive stem bulge, a botanical oddity that is captured in one of its Latin descriptors inflatum. 

Sometimes an oddity is just an oddity, a desert biologist once told me. But something about desert trumpet’s stem bladders seemed, well, to serve a purpose. Could the bulges be galls, ie, abnormal structures that grow in response to insects laying eggs on a plant or their developing larvae chowing down on its tissues?

Thankfully, someone with far more know-how than me explored this question and came up with a rather surprising hypothesis.

In a 2013 blog post, Eric La Fountaine of the University of British Columbia Botanical Garden explored the mystery of desert trumpet’s stem distensions. It turns out that they are not caused by insects even though some insects use the empty chambers as food storage or shelter. According to Eriogonum expert, the late James L. Reveal of the University of Maryland, the stem swellings contain high concentrations of carbon dioxide. La Fountaine speculates that “possibly, the inflations give [desert trumpet plants] photosynthetic advantages—making more CO2 available and providing additional stem surface area to a plant that supports few leaves in the dry desert environment.”

A plant that uses its stem for both feedstock storage and energy production. Brilliant!