Researcher and author Kat Anderson is perhaps best known for her much-loved work, Tending the Wild. Her contributions to ethnobotany and historic ecologies in California have greatly expanded our understanding of the human relationship to native plants. Recently, we were privileged to have Kat serve as our Fremontia guest editor for a beautiful double-issue on geophytes. The following is an excerpt, capturing some of the highlights.
Excerpt from Kat Anderson and Philip Rundel in California Geophytes
In the course of evolution, plant species have developed a myriad of adaptive features that help them survive environmental stress. One such adaptation that has evolved multiple times in diverse lineages is the geophyte growth form. Geophytes have an underground storage organ which allows the plant to die back to the ground and go dormant during unfavorable seasons for growth. Renewal buds associated with the storage organs allow a new cycle of leafing and blooming when favorable conditions return.
Gardeners tend to lump most geophytes as “bulb” plants, but a broad definition of geophytes would include a morphologically diverse group of species that have adapted differing forms of storage organs.
If we think about global ecosystems that experience seasonal stresses where the geophyte growth form may be successful, there are three biomes where these plants are conspicuous components of the flora. The first is the arctic or alpine tundra which has long cold winters. Underground storage organs allow plants to develop vegetative tissues quickly and flower in the short growing season. A second example is the temperate deciduous forests where the understory is heavily shaded in the summer growing season. In these habitats, geophytes can resprout and flower in the late winter or early spring before regrowth of the tree canopy above.
The global sweet-spots for geophytes lie in the world’s Mediterranean-type climate regions, where there is a predictable summer drought. Under these conditions, and with fire as a frequent component of the disturbance regime, the geophytic form of growth provides a highly successful plant strategy of survival. Mediterranean-type climate regions arguably represent the highest diversity of geophytes of any of the world’s biomes.
In the end, technical botanical definitions aside, geophytes are defined in a number of practical manners so long as the intent is clearly stated. While underground storage organs have evolved independently in a number of morphological forms, the ecological function and adaptive strategy is much the same.
Visit our CNPS Geophyte webpage to learn more.
We hope you are enjoying the issue!
Featured image by Scott Hein (www.heinphoto.com)