Invasive Plants

This list of invasive plants was compiled by selecting common invaders found on the central coast from Invasive Plants of California’s Wildlands (edited by Carla C. Bossard, John M. Randall, and Marc C. Hosbovsky, 2000, University of California Press).

Moving the cursor over the plant name on the left will display a picture of that plant in the top and bottom picture panels. To view a list of all pictures on the same page, select the “All Plants” menu option.

It is noted in the book that damage caused by invasive plants in California is widespread and significant. Invasive plants have caused harm to native plants and ecosystems. The foremost cause of the continuing loss of biodiversity in the world is habitat loss and destruction, folllowed by the damage caused by invasive plants. Not all exotic plants are harmful; less than ten percent of introduced non-natives cause problems. However, this small percentage has caused land-altering changes in California.

Much of this damage can be prevented and reversed, if steps are taken in a timely manner. In some instances, time may be critical. Currently there are about a hundred and eighty rare plant species that are threatened by invasive exotics. In some places invasion has been so pervasive, that ecosystem behavior has been significantly altered. In the Great Basin, the infestation of cheat grass has resulted in the increase of fire frequency to once every three to five years, from approximately once every sixty to a hundred years. Where native species are accustomed to longer fire cycles, more frequent fires make recovery more difficult and less likely. Some species, such as the South African Ice Plant absorb a great deal of salt, which is deposited in the soil when the plant dies. This altered, saline soil does not permit the easy re-establishment of native species.

Further information can be found at California Invasive Plant Council.  July 19-25, 2004 has been designated as Invasive Weeds Awareness Week in California by The California legislature.