Mount Tamalpais

The northern, southern and eastern slopes of Mount Tamalpais that are not within the State Park boundaries are included in this area.

A variety of habitats is present, including redwood forest, mixed evergreen forest, chaparral, mountain meadow and riparian. In the mixed evergreen are tan-oak, Lithocarpus densiflorus, madrone, Arbutus menziesii, chinquapin, Chrysolepis chrysophylla, coast live oak, Quercus agrifolia, canyon live oak, Quercus chrysolepis, bay, Umbellularia californica, and Douglas fir, Pseudotsuga menziesii. California nutmeg, Torreya californica, occurs in scattered localities on the mountain.

Chaparral covers much of the mountain and includes such species as Ceanothus spp., chamise, Adenostoma fasciculatum, Arctostaphylos spp., chaparral pea, Pickeringia montana, and silk-tassel bush, Garrya elliptica.

In the wet mountain meadows a number of species are found, including Carex cusickii, Eleocharis obtusa var. engelmanni, Eleocharis rostellata and Juncus kelloggii. White alder, Alnus rhombifolia, big-leaf maple, Acer macrophyllum, and bay occur along the creek banks, with coffeeberry, Rhamnus californica, the most conspicuous member of the understory.

Seven rare plants occur on the mountain: Arctostaphylos hookeri ssp. montana, Arctostaphylos virgata, Cirsium hydrophilum var. vaseyi, Dichondra donnelliana, Eriogonum luteolum var. caninum, Pleuropogon hooverianus and Streptanthus batrachopus. The latter is known from only three localities, two on the mountain and one on nearby Carson Ridge. A number of species have their type locality here. Some 51 species of plants reach their southern distributional limits in the Mount Tamalpais area, while 12 reach their northern limits. At Phoenix Lake several hundred meters north of the area, three species of cattail, Typha angustifolia, Typha domingensis, and Typha latifolia, occur together, the only such occurrence in the State (plus hybrids of Typha angustifolia and Typha latifolia).

Animals are abundant in the area. Mountain lions, Felis concolor, occur here. Among the more noteworthy birds are the spotted owls, Strix occidentalis, which breed here. Wrentits, Chamaea fasciata, are common.

Geologically, Mount Tamalpais is composed of rocks of the Franciscan formation, including melanges. There are no younger rock formations in the area, which would indicate that the mountain has been above sea level as long as any area along the coast. A number of serpentine outcrops are found on the slopes.

Integrity: There are a number of trails and some fire roads. Fire burned portions in 1926 and 1945. As the area is protected as a watershed, much of it has suffered little impact.

Use: Research, educational, observational. Some private.

Ref: Howell, J. T., 1970. Marin Flora, University of California Press, Berkeley, 363 pp.

February 1978