Mt. Tam BioBlitz Finds Rare Plant Species

Small white flower with shades of pink and purple, covered in water droplets
The rare Oakland mariposa lily was recently found during a BioBlitz at Mount Tamalpais State Park.


May 2018 - The Redwood Creek Vegetation program hosted a One Tam BioBlitz in mid-May along Bootjack Creek in Mount Tamalpais State Park. This site was of particular interest to park managers because of its serpentine soils, which are rare within the Redwood Creek watershed, and because only limited botanical surveys have been done here in the past.

Fifteen volunteers observed more than 170 species, including 123 species of plants, 25 species of wildlife, and 20 species of fungus. Highlights from the day include the discovery of a previously unknown population of the rare Oakland mariposa lily (Calochortus umbellatus), and many locally uncommon species such as ninebark (Physocarpus alternans), serpentine coyote mint (Monardella purpurea), and leopard lily (Lilium pardalinum). Inventories like these not only get community members involved in understanding the natural wonders of Mt. Tam, but also offer invaluable information for park managers.

Explore the BioBlitz observations on iNaturalist to learn more.

Last updated: May 31, 2018