Marin County is located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2010 census, the population was 252,409. Its county seat is San Rafael. Marin County is across the Golden Gate Bridge from San Francisco, and is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.
San Mateo County, officially the County of San Mateo, is a county located in the U.S. state of California. As of the 2010 census, the population was 718,451. The county seat is Redwood City. San Mateo County is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area, Silicon Valley, and is part of the San Francisco Bay Area, the nine counties bordering San Francisco Bay. It covers most of the San Francisco Peninsula. San Francisco International Airport is located at the northern end of the county. The county's built-up areas are mostly suburban with some areas being very urban, and are home to several corporate campuses.
Tiburon is an incorporated town in Marin County, California. It is located on the Tiburon Peninsula, which reaches south into the San Francisco Bay. The smaller city of Belvedere occupies the south-west part of the peninsula and is contiguous with Tiburon. Tiburon is bordered by Corte Madera to the north and Mill Valley to the west, but is otherwise mostly surrounded by the Bay. Besides Belvedere and Tiburon, much of the peninsula is unincorporated, including portions of the north side and the communities of Strawberry and Paradise Cay.
Baker Beach is a public beach on the peninsula of San Francisco, California, U.S. The beach lies on the shore of the Pacific Ocean in the northwest of the city. It is roughly a 0.5 mi (800 m) long, beginning just south of Golden Gate Point, extending southward toward the Seacliff peninsula, the Palace of the Legion of Honor and the Sutro Baths. The northern section of Baker Beach is "frequented by clothing-optional sunbathers," and as such it is considered a nude beach.
Richardson Bay is a shallow, ecologically rich arm of San Francisco Bay, managed under a Joint Powers Agency of four northern California cities. The 911-acre (369 ha) Richardson Bay Sanctuary was acquired in the early 1960s by the National Audubon Society. The bay was named for William A. Richardson, early 19th century sea captain and builder in San Francisco. It contains both Strawberry Spit and Aramburu Island.
Potentilla hickmanii is an endangered perennial herb of the rose family. This rare plant species is found in a narrowly restricted range in two locations in coastal northern California, in Monterey County, and in very small colonies in San Mateo County. This small wildflower, endemic to western slopes of the outer coastal range along the Pacific Ocean coast, produces bright yellow blossoms through spring and summer.
Crystal Springs Reservoir is a pair of artificial lakes located in the northern Santa Cruz Mountains of San Mateo County, California situated in the rift valley created by the San Andreas Fault just to the west of the cities of San Mateo and Hillsborough, and I-280. The lakes are part of the San Mateo Creek watershed.
The Mission blue is a blue or lycaenid butterfly subspecies native to the San Francisco Bay Area of the United States. The butterfly has been declared as endangered by the US federal government. It is a subspecies of Boisduval's blue.
Acanthomintha duttonii is a species of annual plant endemic to San Mateo County, California in the family Lamiaceae. It is commonly called San Mateo thornmint and is found growing on serpentine soils near the Crystal Springs Reservoir in a six-mile (10 km) long strip on the east side of Montara Mountain at elevations of approximately 150 to 300 meters.
Pentachaeta bellidiflora, the white-rayed pentachaeta or whiteray pygmydaisy, is a Californian wildflower in the genus Pentachaeta of the family Asteraceae. It is included in both the state and federal lists of endangered species.
Cirsium fontinale, the fountain thistle, is a flowering perennial herb in the sunflower family. It is endemic to California. The genus Cirsium is commonly known as the "thistle" genus, Cirsium being the Greek word for 'thistle.'
Eriophyllum latilobum or San Mateo woolly sunflower is a perennial herb of sharply limited range, endemic and occurring only in the state of California, United States. This flowering plant of the family Asteraceae has been listed as an endangered species by the U.S. federal government as well as the state of California.
Hesperolinon is a genus in the family Linaceae, whose common genus names are dwarf-flax or western flax, in reference to their distribution along the west coast of North America. There are 13 known species within this genus of wildflowers, most of which are limited to serpentine soil habitats within California, United States. These annual plants are thought to be mostly self-pollinating.
Streptanthus niger is an endangered species within the family Brassicaceae. Like other genus members, this herb has wavy petal margins with perimeter calluses that discourage larval herbivory. This plant is endemic to the Tiburon Peninsula of Northern California, and occurs at elevations below 150 m on serpentine grasslands. The common name for this species is Tiburon jewelflower or black jewelflower. This annual herb blooms in May and June and displays dark purple sepals. The etymology of this genus scientific name derives from the Greek word streptanthus, meaning twisted flower, with reference to the notable wavy margins of the petals. The species name niger relates to the color of the seeds being black, although an alternate account cites the dark color of the petals as the source of the appellation.
Hesperolinon breweri is a rare species of flowering plant in the flax family known by the common names Brewer's dwarf flax and Brewer's western flax. It is endemic to California, where it is known from three counties in the San Francisco Bay Area. It is found in chaparral ecosystems, often on serpentine soils. This is an annual herb growing erect to a maximum height near centimeters. Its narrow, linear leaves are greenish to purplish in color. It produces dense inflorescences of flowers with glandular sepals and five bright yellow petals. The protruding stamens hold large orange-yellow anthers. This uncommon California endemic is threatened by development of its habitat but its current status is not known.
Hesperolinon micranthum is a species of flowering plant in the flax family known by the common name smallflower dwarf flax. It is native to the west coast of North America from Oregon to Baja California. It may occur in Nevada. It grows in a number of open habitats, often on serpentine soils. This is a spindly annual herb producing a very thin stem 5 to 20 centimeters in height. Its small, sparse leaves are linear in shape. The tiny flowers have five white or pink-veined white petals each less than four millimeters long and protruding stamens with white or purple anthers.
Hesperolinon serpentinum is a rare species of flowering plant in the flax family known by the common name Napa dwarf flax, or Napa western flax. Hesperolinon serpentinum was not validly published by McCarten although it appears in the Jepson Manual. The species was validly published as Hesperolinon sharsmithae in 2006 by O'Donnell. The species is endemic to northern California, where it is known from fewer than twenty occurrences in four counties surrounding the San Francisco Bay Area. It is a member of chaparral plant communities, generally on serpentine soils. It produces a thin, erect stem up to 30 centimeters tall, with sparse flat, narrow leaves. The inflorescence holds several light yellow flowers with petals only 2 or 3 millimeters long. The plant is threatened mainly by development of its habitat.
Hesperolinon tehamense is a rare species of flowering plant in the flax family known by the common names Tehama County western flax and Paskenta Grade dwarf flax. It is endemic to northern California, where it is known from only about ten occurrences, mostly within Tehama and Glenn Counties. Most of its habitat is on Bureau of Land Management lands and within the Mendocino National Forest, in chaparral ecosystems with serpentine soils. The plant produces thin, hairy stems up to 50 centimeters in maximum height with small, sparse linear leaves. The inflorescence bears several small flowers with pale to bright yellow notched petals just a few millimeters long.
The Bay checkerspot is a butterfly endemic to the San Francisco Bay region of the U.S. state of California. It is a federally threatened species, as a subspecies of Euphydryas editha.
