Featured Plant

Different species of Gunnera can be found living around the globe today, from Mexico to Latin America, Hawaii, islands in the South Pacific, Southeast Australia, New Zealand, Africa, and Madagascar. In spite of this apparent broad distribution, pollen fossils from around the world indicate Gunnerapopulations were much more expansive in the distant past, with pollen specimens found in Russia, India, Eastern Europe, and North America, among other locations. Researchers propose the decrease in distribution may be related to the decrease in rainfall and increase in temperature fluctuations experienced by these earlier-inhabited regions. Today, all Gunnera species are isolated to environments with heavy rainfall. 

With an introduction to ornamental horticulture, Chilean rhubarb has become invasive in environments where humidity and water are readily available. The United Kingdom, the Azores Islands of Portugal, New Zealand, and the coastal Bay Area of California have all become satellite homes to this strong competitor. Both Point Reyes National Seashore and Tomales Bay State Park host naturalized colonies of Gunnera tinctoria. With this species’ affinity for our maritime climate and small seed that is likely distributed by wind and water (and perhaps on the feet of birds), this is a specimen that should be cultivated with caution in our region. At the San Francisco Botanical Garden, flower stalks responsible for producing seed are pruned and composted annually prior to seed maturation. 
 

IN BLOOM CONTRIBUTORS: Text by Corey Barnes and Profile by Mona Bourell. Photos by Joanne Taylor and David Kruse-Pickler.