Though outcrops consitute only about 1% of California's landmass, Serpentine was named the official State Rock in 1965. Photo by Eric in SF on Flickr.

Serpentine areas are often easy to spot, because of their apparent 'barren' look, but they can contain unusual and beautiful rare endemic species that grow nowhere else. Photo by Jeff Hapeman on Flickr.

plants that show tolerance of

serpentine soils

Serpentine soils, weathered from ultramafic rock, exist in various part of the world. Because of the low calcium-magnesium ratio, lack of essential nutrients such as nitrogen, potassium, and phosphorus, and high concentrations of the heavy metals, plant species can fail to hrive or outright be killed when grown in these soils. In additon, these soils may also contain asbestos, an additional risk to humans and animals.

Covering such soils with vegetation is certainly desireable, but problematic. Many species seems to start growing well, only to suddenly fall victum to poisoning when their roots penetrate higher levels of serpentine. Depending upon growing conditions (exposure, available water, etc.), the plants in this list have demonstrated tolerance to these soils. While not a guarantee of success, these plants are certainly good risks.

There are also a number of species that have become completely adapted to these soils, called narrow endemics, only able to grow under these unusual conditions. If you have serpentine soil 'problem', you may also have some of these very rare plants - worth researching carefully before planting.

Aesculus Californica — California buckeye

Acer macrophyllum — big-leaf maple

Aquilegia eximia — Van Houtte's columbine

Arbutus menziesii — madrone

Arctostaphylos obispoensis — serpentine manzanita

Artemisia california — California sagebrush

Artemisia 'Montara' (natural hybrid of A. californica × A. pycnocephala ?)

Asclepias cordifolia — purple milkweed

Ceanothus foliosus — wavy-leaf mountain lilac

Ceanothus jepsonii — musk bush

Ceanothus 'Mills Glory' — hybrid ceanothus

Ceanothus papillosus — wart-stem ceanothus

Ceanothus purpureus — holly-leaf ceanothus

Ceanothus roderickii — Pine Hill ceanothus

Cercis occidentalis — California redbud

Cercis orbiculata — see Cercis occidentalis

Cercocarpus betuloides — mountain mahogany

Cupressus macnabiana — MacNab cypress

Cupressus sargentii — Sargent's cypress

Dendromecon rigida — bush poppy

Diplacus aurantiacus — sticky monkey flower

Epilobium canum — hummingbird trumpet

Equisetum hymale — horse-tail

Erigeron glaucus — seaside daisy

Eriodictyon californicum — yerba santa

Eriogonum fasciculatum — Eastern mohave buckwheat

Eriogonum nudum — naked buckwheat

Fremontodendron californicum — flannelbush

Garrya elliptica — silk tassel

Gnaphalium californicum — California pearly everlasting

Grindella hirsutula — hairy gumweed

Helianthemum scoparium — sun rose

Hesperoyucca whipplei — Our Lord's candle

Holodiscus discolor — oceanspray

Hordeum brachyantherum subsp. californicum — California barley

Iris douglasiana — Douglas iris

Juniperus communis var. jackii — juniper

Keckiella sp. — bush penstemon

Lepechinia calycina — woodbalm

Libocedrus decurrens — insense cedar

Lithocarpus densiflorus subsp. echinoides — dwarf tabbark oak

Mahonia pinnata — shiny-leaf mahonia

Mimulus cardinalis — scarlet monkey flower

Monardella villosa — coyotemint

Muhlenbergia rigens — deergrass

Paeonia californica — California peony

Pinus coulteri — Coulter pine

Pinus sabiniana — California foothill pine

Polypodium californicum — polypody fern

Prunus ilicifolius — hollyleaf cherry

Quercus chrysolepis — canyon live oak

Quercus durata — leather oak

Quercus kelloggii — California black oak

Quercus ×moreha (kelloggii × wislizeni) — oracle oak

Ranunculus californicus — buttercup

Rhamnus californica — California buckthorn

Rosa gymnocarpa — wood rose

Rosa spithamea — ground rose

Ribes speciosum — fuchsia-flowered gooseberry

Salvia mellifera — black sage

Salvia sonomensis — creeping sage

Salvia spathacea — hummingbird sage

Senecio clevelandii — Red Hills ragwort

Sidalcea malvaeflora — checkerbloom

Stachys ajugoides — pink hedge nettle

Styrax benzoin — styrax

Thermopsis macrophylla — Santa Ynez goldenbanner

Toyon arbutifolia — toyon

Umbellularia californica — Califonia laurel

Yucca whipplei — see Hesperoyucca whipplei

Zauschneria — see Epilobium canum

Bibliography

Elkins, R., Frazell, J., O'Green, A.T., Reynolds, R. Trees and Shrubs for Northern California Serpentine Landscapes (ANR Publication 8400). UC Division of Agriculture and Natural Resources. October, 2009: Print. <celake.ucdavis.edu> (pdf).

Kruckenberg, Art. The Serpentine Story. Kruckenberg Botanica Garden News. August, 2008: Print. <www.kruckeberg.org> (pdf).

Lake County Air Quality Management District & UC Cooperative Extension Master Gardeners Lake County Serpentine Landscape Demonstration Garden. (handout) Print. <www.capcoa.org> (pdf).

Wilson, Bert. Northern California Lilacs. Las Pilitas Nursery. Web. <www.laspilitas.com>.