Rare Serpentine Endemic Plants of the Klamath-Siskiyou Bioregion
The Klamath-Siskiyou bioregion, the Klamath Province or Klamath-Siskiyou Ranges, is a meeting ground for species from the Cascade Range to the north, California Floristic Province species from Mexico, Sierra Nevada, and the California Coast Ranges. Many of these species find themselves at the margins of their geographic ranges in the Klamath-Siskiyou bioregion. Even the Great Basin flora has sent a finger west across the Shasta Valley, north of Mt. Shasta, into the southeastern corner of the Klamath Ranges in the Eddy and Scott Mountains, where big sagebrush (Artemisia tridentata), bluebunch wheatgrass (Pseudoregneria spicata), curlleaf mountain-mahogany (Cercocarpus ledifolius), and even greasebush (Glossopetalon spinescens) rub shoulders with serpentine endemics.
The result of this rich floristic diversity coupled with the long geologic history of the Klamath-Siskiyou Ranges, complex topography, geology, and soils, and a Mediterranean climate with a strong moisture and temperature gradient from the coast inland, is a very distinct regional flora with many rare and not-so-rare plants that are found only in the Klamath-Siskiyou bioregion. Some of these plants are restricted to serpentine, some are not.
The list of rare Klamath-Siskiyou serpentine endemics presented here includes only those plants that are confined to this bioregion. Rare plants that are shared with other regions are not shown. More common endemics (G4 or G5 ranked) are also not included, plants such as Del Norte willow (Salix delnortensis) and Brewer spruce (Picea breweriana), the latter a well known relict of the Arcto-Tertiary forest, which persists now only in the Klamath Ranges.
Lomatium tracyi. Photo by Br. Alfred Brousseau, College of St. Mary, California.
Our thanks to CalPhotos and its many contributors for many of the pictures in this photo gallery.