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.

Photo Gallery

Arabis koehler var. stipitata
Arabis koehler var. stipitata. Photo by D. Imper © CNPS.

Arabis macdonaldiana
Arabis macdonaldiana. Photo by John McRae.

Rare Plant Profile.

Arctostaphylos canescens ssp. sonomensis
Arctostaphylos canescens ssp. sonomensis. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Arctostaphylos canescens ssp. sonomensis
Arctostaphylos canescens ssp. sonomensis. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Arctostaphylos klamathensis
Arctostaphylos klamathensis. Photo by Julie Kierstead Nelson.

Chaenactis suffrutescens
Chaenactis suffrutescens. Photo by Shauna Hee.

Chaenactis suffrutescens
Chaenactis suffrutescens. Photo by Shauna Hee.

Cypripedium californicum
Cypripedium californicum. Photo by Br. Alfred Brousseau, College of St. Mary, California.

Draba carnosula
Draba carnosula. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Epilobium siskiyouense
Epilobium siskiyouense. Photo by Ken DeCamp.

Ericameria ophitidis
Ericameria ophitidis. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Eriogonum alpinum
Eriogonum alpinum. Photo courtesy of the Shasta-Trinity National Forest.

Eriogonum congdonii
Eriogonum congdonii. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Eriogonum hirtellum
Eriogonum hirtellum. Photo by J. Knorr.

Eriogonum hirtellum
Eriogonum hirtellum. Photo by J. Knorr.

Arctostaphylos klamathensis
Eriogonum hirtellum habitat. Photo by J. Knorr.

Eriogonum libertini
Eriogonum libertini. Photo by Shauna Hee.

Eriogonum libertini
Eriogonum libertini. Photo by Susan Erwin.

Galium serpenticum ssp. scotticum
Galium serpenticum ssp. scotticum. Photo courtesy of the Shasta-Trinity National Forest.

Harmonia doris-nilesiae
Harmonia doris-nilesiae. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Harmonia doris-nilesiae
Harmonia doris-nilesiae. Photo by Shauna Hee.

Ivesia pickeringii
Ivesia pickeringii. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Lomatium engelmannii
Lomatium engelmannii. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Lomatium tracyi
Lomatium tracyi. Photo by Br. Alfred Brousseau, College of St. Mary, California.

Lupinus croceum
Lupinus croceum. Photo by Julie Kierstead Nelson.

Lupinus croceum
Lupinus croceum. Photo by Julie Kierstead Nelson.

Lupinus lapidicola
Lupinus lapidicola. Photo by Br. Alfred Brousseau, College of St. Mary, California.

Minuartia rosei close-up
Minuartia rosei. Photo by Shauna Hee.

Minuartia rosei habitat
Minuartia rosei habitat. Photo by Shauna Hee.

Orthocarpus pachystachyus
Orthocarpus pachystachyus. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Penstemon filiformis
Penstemon filiformis. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Perideridia erythrorhiza
Perideridia erythrorhiza. Photo by Lois Shoemaker.

Phacelia greenei
Phacelia greenei. Photo by Dr. Dean William Taylor, Jepson Herbarium.

Phacelia dalesiana
Phacelia dalesiana. Photo by Julie Kierstead Nelson.

Phacelia leonis
Phacelia leonis. Photo by Julie Kierstead Nelson.

Phacelia leonis
Phacelia leonis. Photo by Susan Erwin.

Potentilla cristae
Potentilla cristae. Photo by John Game.

Raillardella pringlei
Raillardella pringlei. Photo by Shauna Hee.

Raillardella pringlei
Raillardella pringlei. Photo by Shauna Hee.

Raillardella pringlei
Raillardella pringlei. Photo by Julie Kierstead Nelson.

Sedum moranii
Sedum moranii. Photo by Norman Jensen, Photo·grafica botanii.

Sedum moranii habitat
Sedum moranii habitat. Photo by Norman Jensen, Photo·grafica botanii.

Silene salmonacea
Silene salmonacea. Photo by Susan Erwin.

Silene serpentinicola
Silene serpentinicola. Photo by Norman Jensen, Photo·grafica botanii.

Streptanthus drepanoides
Streptanthus drepanoides. Photo by Patrick McIntyre.

Tauschia howellii
Tauschia howellii. Photo by Br. Alfred Brousseau, College of St. Mary, California.

Thlaspi californicum
Thlaspi californicum. 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.