a wide variety of plant communities as well. Plant communities on the mountain include various types of hardwood and coniferous forests, coastal scrub, chaparral, grassland, and wetland vegetation. Wholly or partially coniferous forest types are found in the moistest areas of Mount Tamalpais. Coast redwood forests are restricted to areas where the particular ecological needs of redwood are met: areas characterized by high overall moisture, low elevations below the fog line, and deep soils. Muir Woods is the most extensive and best-known redwood forest of the Mount Tamalpais area. Mixed evergreen forests of various combinations of tanoak, madrone, coast and canyon live oak, and Douglas-fir are found in moist areas on middle to high elevations on the mountain. Very moist areas of mixed evergreen forest may also include bay, redwood, and California torreya. Areas in which mixed evergreen forests are predominant include areas of Fairfax-Bolinas Road and Ridgecrest Boulevard and around Alpine Lake. Various kinds of scrub communities are also widespread. Low-elevation areas below the fog line with relatively low overall rainfall or thin soils are often the site of a northern coastal scrub community characterized by coastal sage-coyote brush association, with lesser amounts of poison-oak, bush monkeyflower, California blackberry, western bracken fern, and various species of grasses and forbs. Chaparral is predominant in areas characterized by thin, rocky soils and little moisture. Two main types of chaparral are found the mountain chamise chaparral and manzanita chaparral. Chamise is dominant in the hottest, most xeric areas of the mountain, particularly on south- and west-facing slopes, while manzanita is dominant in other xeric areas, particularly on east-facing slopes and forest borders. Areas of mixed chamise-manzanita chaparral occur in relatively more mesic areas; Ceanothus and dwarfed interior live oak may also predominate on such sites. Areas in which various kinds of chaparral communities are dominant include areas along Old Railroad Grade. Grassland areas are also common on Mount Tamalpais. Native perennial bunchgrass species were originally dominant, but most of these grasslands are now dominated by invasive annual grasses of European origin. Native grasslands, still found in a few isolated areas, are of two types. Northern coastal prairie is found below the fog line and is characterized by a Festuca-Danthonia association, while valley grassland, found in drier areas, is dominated by Nassella pulchra, with Elymus glaucus and Leymus triticoides also being common. Wetland vegetation types found on Mount Tamalpais include coastal riparian forests,