Regularity: Regularly occurring
Global Range: Endemic to California, known only from Olcott Lake and vicinity.
Catalog Number: US 2241392
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Card file verified by examination of alleged type specimen
Preparation: Pressed specimen
Collector(s): B. Crampton
Year Collected: 1958
Locality: 1/2 mi S of Olcott, 12 mi S of Dixon., Solano, California, United States, North America
- Isotype: Crampton, B. 1959. Madrono. 15: 107.
California Central Valley Grasslands Habitat
This taxon is found in the California Central Valley grasslands, which extend approximately 430 miles in central California, paralleling the Sierra Nevada Range to the east and the coastal ranges to the west (averaging 75 miles in longitudinal extent), and stopping abruptly at the Tehachapi Range in the south. Two rivers flow from opposite ends and join around the middle of the valley to form the extensive Sacramento-San Joaquin Delta that flows into San Francisco Bay.
Perennial grasses that were adapted to cool-season growth once dominated the ecoregion. The deep-rooted Purple Needle Grass (Nassella pulchra) was particularly important, although Nodding Needle Grass (Stipa cernua), Wild Ryes (Elymus spp.), Lassen County Bluegrass (Poa limosa), Aristida spp., Crested Hair-grass (Koeleria pyramidata), Deergrass (Muhlenbergia rigens,), and Coast Range Melicgrass (Melica imperfecta) occurred in varying proportions. Most grass growth occurred in the late spring after winter rains and the onset of warmer and sunnier days. Interspersed among the bunchgrasses were a rich array of annual and perennial grasses and forbs, the latter creating extraordinary flowering displays during certain years. Some extensive mass flowerings of the California Poppy (Eschscholzia californica), Lupines (Lupinus spp.), and Exserted Indian Paintbrush (Castilleja exserta) are found in this grassland ecoregion.
Prehistoric grasslands here supported several herbivores including Pronghorn Antelope (Antilocapra americana), elk (including a valley subspecies, the Tule Elk, (Cervus elaphus nannodes), Mule Deer (Odocoileus hemionus), California ground squirrels, gophers, mice, hare, rabbits, and kangaroo rats. Several rodents are endemics or near-endemics to southern valley habitats including the Fresno Kangaroo Rat (Dipodomys nitratoides exilis), Tipton Kangaroo Rat (Dipodomys nitratoides nitratoides), San Joaquin Pocket Mouse (Perognathus inornatus), and Giant Kangaroo Rat (Dipodomys ingens). Predators originally included grizzly bear, gray wolf, coyote, mountain lion, ringtail, bobcat, and the San Joaquin Valley Kit Fox (Vulpes velox), a near-endemic.
The valley and associated delta once supported enormous populations of wintering waterfowl in extensive freshwater marshes. Riparian woodlands acted as important migratory pathways and breeding areas for many neotropical migratory birds. Three species of bird are largely endemic to the Central Valley, surrounding foothills, and portions of the southern coast ranges, namely, the Yellow-billed Magpie (Pica nuttalli), the Tri-colored Blackbird (Agelaius tricolor EN), and Nuttall’s Woodpecker (Picoides nuttallii).
The valley contains a number of reptile species including several endemic or near-endemic species or subspecies such as the San Joaquin Coachwhip (Masticophis flagellum ruddocki), the Blunt-nosed Leopard Lizard (Gambelia sila EN), Gilbert’s Skink (Plestiodon gilberti) and the Sierra Garter Snake (Thamnophis couchii). Lizards present in the ecoregion include: Coast Horned Lizard (Phrynosoma coronatum NT); Western Fence Lizard (Sceloporus occidentalis); Southern Alligator Lizard (Elgaria multicarinata); and the Northern Alligator Lizard (Elgaria coerulea).
There are only a few amphibian species present in the California Central Valley grasslands ecoregion. Special status anuran taxa found here are: Foothill Yellow-legged Frog (Rana boylii NT); Pacific Chorus Frog (Pseudacris regilla); and Western Spadefoot Toad (Pelobates cultripes). The Tiger Salamander (Ambystoma tigrinum) occurs within this ecoregion.
Although many endemic plant species are recognized, especially those associated with vernal pools, e.g. Prickly Spiralgrass (Tuctoria mucronata). A number of invertebrates are known to be restricted to California Central Valley habitats. These include the Delta Green Ground Beetle (Elaphrus viridis CR) known only from a single vernal pool site, and the Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus) found only in riparian woodlands of three California counties.
Vernal pool communities occur throughout the Central Valley in seasonally flooded depressions. Several types are recognized including valley pools in basin areas which are typically alkaline or saline, terrace pools on ancient flood terraces of higher ground, and pools on volcanic soils. Vernal pool vegetation is ancient and unique with many habitat and local endemic species. During wet springs, the rims of the pools are encircled by flowers that change in composition as the water recedes. Several aquatic invertebrates are restricted to these unique habitats including a species of fairy shrimp and tadpole shrimp.
- World Wildlife Fund & C. Michael Hogan. 2013."California Central Valley grasslands". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Mark McGinley.
- Michael G.Barbour, Todd Keeler-Wolf and Allan A. Schoenherr. 2007. Terrestrial vegetation of California. 712 pages
Comments: Germinates in warm, turbid, somewhat alkaline vernal pools; these dry out by early summer.
Life History and Behavior
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Known from only 3 vernal pools in Solano and Yolo counties, California. The number of plants varies greatly at each pool from year-to-year. No plants have been seen since 1993 at the type locale. At a second site the number of observed individuals has varied from a single plant to about 150. The third site, discovered in 1993 on what was then Department of Defense land, was observed to have several thousand plants in 2000 (Sacramento Fish and Wildlife Endangered Species Program 2003). This is the only large population known. The site is being transferred to the Yolo County Parks Department.
Date Listed: 09/29/1978
Lead Region: California/Nevada Region (Region 8)
Listing status: E
For most current information and documents related to the conservation status and management of Tuctoria mucronata, see its USFWS Species Profile
Global Short Term Trend: Unknown
Global Long Term Trend: Unknown
Degree of Threat: Very high - high
Comments: Nonnative plants are a threat (CNPS 2001).
The grass Tuctoria mucronata, which is known by several common names including Solano grass, Crampton's tuctoria, and prickly spiralgrass, is a federally listed endangered plant species endemic to two counties in northern California. It is a small annual, with stems growing decumbent against the ground to a maximum length of 12 cm, and turning upward at the tips. The leaves are 2-4 cm long, and secrete a sticky, aromatic juice. In the spring, the grass bears a small inflorescence 1.5-6 cm long, with numerous crowded spikelets.
Solano grass is a vernal pool plant. It is only found in these seasonally wet areas, a type of habitat which is endangered. This species is thought to have once grown in isolated parts the northern Sacramento-San Joaquin Delta, in areas which flooded during the wet season, but any former habitat there has been long since reclaimed for agriculture. Only a few individuals of the plant now exist, mostly in Yolo County. It was found during the 1990s at Jepson Prairie Preserve, an area dedicated to conserving vernal pool habitat, but it may no longer exist there.
Loss of critical habitat is the main cause of the near extinction of Solano grass. This loss is caused by land reclamation for development, recreation, and agricultural use, including for grazing animals, fertilizer runoff, and disturbance of the natural hydrology of the Central Valley. Invasive plants have also played a role in crowding out more delicate native grasses, such as Solano grass, Greene's tuctoria (Tuctoria greenei), Colusa grass (Neostapfia colusana), and several species of genus Orcuttia.
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