Photographs and text by Karen I. Callahan.

My photographs are an introduction to just a few of the dozens of rare plant species of the Sierra Nevada. For example, in Placer and Nevada Counties there are an estimated 2,500 native plant species. Of these, about 90 are considered rare, unusual or sensitive and, of these, 5 are listed by the state or federal government as “rare and endangered”. I hope that the descriptions of the plants’ natural history will inspire your interest in the preservation of our biological resources.

I first became interested in the plight of rare plants while volunteering as a photographer for the botany program of the Tahoe National Forest.  I spent time over several years photographing and monitoring some of the sensitive plant species of the northern Sierra. Monitoring often meant searching for reported locations of plants that hadn’t been visited for several seasons. It was a memorable experience to search for very rare plants and, then, to see so many of them flowering in their beautiful and often unusual habitats.

At present, I am the Rare Plant Chairperson for the Redbud Chapter, California Native Plant Society, for Placer and Nevada Counties. More information about rare plants is available at “cnps.org”. Try “calfora.org” for detailed information about specific plant species. My email address is Penstemon_Callahan@yahoo.com.

Allium sanbornii, Sanborn’s Onion.

Pictured is Sanborn’s Onion, a native wild onion that grows from a small (less than 1”) bulb. The plant produces only one narrow, rounded leaf and one flowering stalk each year. Flowers appear from late June to July. The bright pink flower clusters are quite noticeable against their usual background of dry grasses and bare rocks. Sanborn’s Onion is typically found in small, scattered populations on serpentine or volcanic soils in the northern Sierra Foothills, northern California and southern Oregon below 5,000 feet. Although delicate in appearance, the plant is adapted to survival in a very hot, dry, rocky environment.

Allium sanbornii is included as a sensitive species in the Inventory of Rare and Endangered Plants, Sixth Edition published by the California Native Plant Society. As an example of the worsening conditions for Sanborn’s Onion, almost all of the Alliumsanbornii populations in Nevada County grow on private land and two of the largest populations are directly in the path of commercial land development.

Calystegia stebbinsii, Stebbins’ Morning Glory

Stebbins’ Morning Glory has typical cream-colored Morning Glory flowers, but its distinctive leaves are hairy and deeply divided. Each leaf of this perennial vine has 7 to 9 lance-shaped lobes. The species is also called the El Dorado Morning Glory.

Calystegia stebbinsii is described as “an early successional species”.  The plants grow in temporary openings on gabbro or serpentine soils and are eliminated as dense vegetation grows up around the plants. Stebbins’ Morning Glory also requires fire (or at least some major disturbance) for seed germination. This characteristic makes conservation very difficult as the areas near the Calystegia stebbinsii habitat in El Dorado and Nevada Counties are developed. Stebbins’ Morning Glory is adapted to the unusual soil type known as “gabbro”. Gabbro rocks and soils are found from Plumas to Tuolumne Counties in the Sierra Nevada.

Stebbins’ Morning Glory is officially listed as “rare and endangered” by the Federal government. This is the highest legal protection under the Endangered Species Act. However, even Federally listed plant species are not protected from destruction on privately owned land. The Pine Hill area of El Dorado County is home to Stebbins’ Morning Glory and seven other rare plants. Part of Pine Hill is a preserve managed by several public agencies to protect the rare plants. In Nevada County, Calystegia stebbinsii grows on public and private land with no designated preserve at the present time.

Clarkia biloba ssp. brandegeae, Brandegee’s Clarkia.

Clarkias are showy California native annuals and their colors add to the beauty of the Sierra spring landscape.  Some species used in commercial flower seed mixes have names like “fare-well-to-spring”, “fairy fans”, “red ribbons”, and “summer’s darling”.  There are about 40 species of Clarkia, almost all in western North America.

The photograph shows a rare subspecies of the Bilobed Clarkia. The heart- shape of the bright pink petals with their shallow lobes is a unique characteristic. Also characteristic are the drooping flower buds and eight pollen-bearing anthers.  The plants are less than 3 feet tall.

Brandegee’s Clarkia is found in dry habitats below 2,500 feet in six counties of the northern Sierra. It typically grows on gravelly slopes above creeks and rivers and along roadsides.  Brandegee’s Clarkia may bloom from May to July depending on weather conditions and location.

Cypripedium fasciculatum, Clustered Lady-Slipper Orchid

The rare Clustered Lady-Slipper, like many other native orchids, depends on a mutually beneficial relationship with forest fungi for its seed germination and growth. The Clustered Lady Slipper’s reproduction from seed is slow, but it is known to have a life span of over 30 years. These Orchids grow in forests below 6,000 feet in the northern Sierra Nevada. Cypripedium fasciculatum is a rare species in California, Oregon, Idaho, and Washington. The Lady Slipper Orchids are especially impacted by timber harvesting, road clearing, and the illegal collecting of wild plants.

The Clustered Lady-Slipper Orchid’s pollination strategy involves attracting small wasps into its flower’s lower petal that forms the “slipper”.  The insects have only one way out of the slipper trap—a narrow passage that dusts them with pollen before exiting. Hopefully, the wasps will then visit and transfer the pollen to other, nearby orchid flowers.

Darlingtonia californica, California Pitcher Plant.

The Pitcher Plant was one of the first California native plants to be protected by state law.  People are fascinated by its beauty and biology.  Plant enthusiasts are also tempted to collect the wild plants and take them home. People dig up the Pitcher plant without realizing that the plant will only survive in an unusual fen, seep, or bog environment. For example, the plants require constant, cold, flowing water of a particular acidity.

The “pitcher” is a modified leaf one to two feet high. Insects are attracted to the pitcher and, once inside, cannot escape. The pitcher contains digestive liquids and the digested insects eventually provide nutritional elements lacking in the habitat’s soils. The Darlingtonia’s unusual yellow and red flower grows on a stalk above the leaves.

The Pitcher Plant (also called the Cobra Lily) is found in the northern Sierra Nevada, northern California and southern Oregon. Threats to these unusual plants include logging, mining, alteration of water flows, and illegal collecting.  Darlingtonia californica is also included in CITES, the international agreements to ban trade in endangered species of plants and animals.

Fritillaria agrestis, Stinkbells.

Like most Fritillaries, “Stinkbells” is an early spring bloomer with nodding flowers. This bell shape protects the plant’s reproductive parts from rain and snow. Stinkbells is named for its unpleasant (to most humans!) flower odor.  The odor apparently attracts small native flies to visit the flowers and aid fertilization. The plant is less than two feet high with several small flowers and leaves on the single stem.  Fritillaries grow from bulbs and are members of the Lily Family (Liliaceae).

Stinkbells’ habitat is heavy clay soil in grasslands below 1,500 feet. The flower colors vary from greenish white to yellow to violet depending on location in the foothills of the Sierra Nevada and inner coast ranges. A few populations of Fritillaria agrestis still grow near the urbanized areas of Lincoln, Roseville, Marysville, and North Sacramento.

Lilium humboldtii ssp. humboldtii, Humboldt Lily

It’s a joy to see the brilliant orange flowers of this wild lily along the back roads of the Sierra foothills.  Humboldt Lilies flower in late June to early July and grow in dry forest habitats from 1,800 to 4,000 feet elevation. The pure orange petals have unmargined, maroon-colored spots.  The lily is usually about three to four feet tall with whorls of wavy, smooth green leaves along the single main stem. Another wild lily Lilium pardalinum, Leopard Lily, is easily confused with the Humboldt Lily. The Leopard Lily grows in wet habitats (in meadows and near creeks) and its spotted petals are shades of both red and orange.

Development from lily seed to a flowering plant may require ten years.  The seed first germinates underground, then produces a single leaf above ground. The young plant gradually produces more leaves each year.  Humboldt Lilies adapt to the summer drought conditions of California by using the ability to adjust the depth of its bulb and roots.  Like many other native lilies, the leaves dry out after flowering and seedpod development. Humboldt Lilies are very difficult to grow from seed and their bulbs rarely survive transplanting from the wild. 

Although familiar in many areas, the Humboldt Lily is actually a threatened species as its forest habitat is cleared for homes and roads. The California Native Plant Society describes the Humboldt Lily as “endemic to California, a plant of limited distribution, and endangered in a portion of its range”.  There is rapid human population growth in much of its range from Fresno County north to Tehama County. In addition, Humboldt Lilies are a favorite snack for deer and other animals. 

Lewisia kelloggii, Kellogg’s Lewisia

Lewisia kelloggii is a small, unusual plant of open, gravelly high elevation (5,500 to 8,500 feet) habitats in the Sierra Nevada. This perennial plant produces succulent leaves within a few weeks after the heavy snow pack melts. It then flowers for a short time before drying in its desert-like habitat. The plants virtually disappear by mid-summer. Kellogg’s Lewisia grows about three inches tall from an enlarged underground stem called a “caudex”.

Genetic studies of Lewisia kelloggii conducted by researchers for the US Forest Service  revealed that each scattered population in the Sierra Nevada varies greatly from other populations. Although it is not now listed in the Inventory of Rare and Endangered Species, the new information about the Lewisia’s  genetics will hopefully lead to the species’ protection in every part of its range. A disjunct population of Kellogg’s Lewisia found in the mountains of Idaho was long considered to be the same species. The recent genetic research has shown that the Idaho plants are not closely related. The Idaho plants are proposed as a separate species, Lewisia sacajaweana, to honor Sacajawa, the Native American woman who guided Lewis and Clark’s Voyage of Discovery.

The Lewisia’s open, flat habitat has been used for logging landings, camping, and parking areas in the high country from Plumas County to Fresno County. 

Sidalcea stipularis, Scadden Flat Checkerbloom

The pink-flowered Scadden Flat Checkerbloom grows in fresh water marshes at about 2,200-feet. Since the Gold Rush Era, Sierra foothill wetlands habitats have been very changed by human activities.  Alteration of waterways, grazing, mining, and clearing for building has impacted many plants and animals of our region. Scientists don’t know if the Scadden Flat Checkerbloom was more widespread previously, or if it is just not able to compete with invasive plants.  The plants seem to lack a method of successfully spreading seeds to new places and depend more on increase by root growth.

Sidalcea stipularis is named for its distinctive “stipules” which are leafy structures at the base of the stems. The white streaked pink flowers resemble small hibiscus or mallow flowers. This species is recognized by the California Department of Fish and Game as “rare and endangered” and is found at only two locations in the Grass Valley area.

Viola tomentosa, Woolly Violet

The Woolly Violet is found in scattered populations in dry forest openings at 5,000 to 6,600 feet. There are several species of yellow-flowered violets in our region, but Viola tomentosa is the only one with white woolly hairy, or “tomentose”, leaves.

This Violet grows only in the Sierra Nevada in El Dorado, Placer, Nevada, Sierra, and Plumas Counties. Recreation activities, timber harvesting, road building, and off-highway-vehicles impact this rare species and its rocky habitat.  Woolly Violet is on the sensitive species list for the Tahoe National Forest. The National Forests have a policy to consider impacts to rare and sensitive species in forest logging plans or other activities.