While people connect easily with the spectacular recovery of the American bald eagle, California elephant seal, or other endangered wildlife, they may be less aware of the wildflowers underfoot or the subtly fragrant shrublands along the trail.
Due to San Francisco's unique geology, extent of urban development, and biogeographic isolation, the city harbors rare and fragile native plant communities.
These special ecological areas harbor 17 rare and endangered plant species (PDF), as can be seen listed below. Most of these endangered members of the San Francisco flora grow nowhere else but here in the Bay Area, and some only in the City itself!
The Presidio's watersheds harbor five federally-listed endangered plant species in their dunes and serpentine soils. San Francisco is truly an ecological refuge for these rare plants that need our very special micro-habitats to survive, and which are vital members of our City's biological diversity.
Coast Rock Cress (Arabis blepharophylla)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Franciscan Manzanita (Arctostaphylos franciscana)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Presidio Manzanita (Arctostaphylos montana ssp. Ravenii)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
San Francisco Bay Spineflower (Chorizanthe cuspidata var. Cuspidate)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Franciscan Thistle (Cirsium andrewsii)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Presidio Clarkia (Clarkia franciscana)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
San Francisco Collinsia (Collinsia multicolor)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
San Francisco Wallflower (Erysimum franciscanum)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Blue Coast Gilia (Gilia capitata ssp. Chamissonis)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Hairy/San Francisco Gumplant (Grindelia hirsutula)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Marin Western/Dwarf Flax (Hesperolinon congestum)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Kellogg' Horkelia (Horkelia cuneata var. sericea)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Coast Iris (Iris longipetala)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
San Francisco Lessingia (Lessingia germanorum)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
Michael's Rein Orchid (Piperia michaelii)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
San Francisco Campion (Silene verecunda ssp. verecunda)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
California Seablite (Suaeda californica)
Formerly more widespread in San Francisco Bay Area, where now nearly extirpated by development; currently only known from fragmented populations in SF Bay Area and Morro Bay. Remains from adobe bricks indicate plant may once have occurred along the Petaluma River. Threatened by development, recreational activities, erosion, non-native plants, and alteration of marsh habitat.
