Can you believe I’m still not done with the Death Valley report?
Every once in awhile a plant interests me for some reason other than the flowers. I love the finely-cut foliage of Thalictrum species, for instance, or the growth habit of Sedum ternatum.
Though the minuscule flowers are lovely, the main attraction of this strange plant is the swollen stems below the nodes. For years people believed that the swelling had something to do with the life cycles of wasps and gall insects, but this notion was proven false by the University of Maryland’s Dr. James L. Reveal, who showed that these nodes are actually carbon dioxide tanks, so to speak. I haven’t been able to find out why a plant would need to store carbon dioxide, and annoyingly can’t find the papers in which Dr. Reveal published this information.
The genus name is from the Greek words for wool (erio) and knee (gono), though this particular species does not actually have woolly knees. It’s a perennial that can grow up to 2′ tall, and is a very common plant in the deserts of California, Nevada, Utah, Arizona, New Mexico, and Colorado.
The unswollen parts of the stems are slender, making this a difficult plant to photograph.