Field Trip Reports – February, 2026

20250221 Lichens of Mt. Tam, hosted by East Bay Chapter

Klara Schnarnagl is the Tucker Curator of Lichenology at the Jepson Herbarium at UC Berkeley. On February 21, she led two lichen walks for CNPS East Bay Chapter on Mt. Tamalpais. I attended her afternoon session and learned just enough to possibly identify our most common lichens on upcoming Marin Chapter field trips.

Lichens are a mutualistic relationship between fungi and algae and/or cyanobacteria with maybe some yeast joining the team. They are named and identified by the fungus which is the structural part of the organism. The very small algae live near the top layer of fungal hyphae and photosynthesize, sharing their created sugars with their host fungus. The fungus share other nutrients with the algae.

The almost 20,000 species of lichen in the world come in three main physical forms: crustose, foliose, and fruticose, respectively flat crust on substrate, 3-dimentional flattish layers, more 3-dimentional to even hanging.

California is home to thousands of lichens. Some of the common ones in Marin are ruffle lichens, old man’s beards (Usnea), lace lichen (our state lichen Ramalina menziesii), and common greenshield lichen. Others are bright green map lichen, pixie cup lichen, and cheerio lichen. Lichens most often are brown to “lichen” green in color. Some turn brighter when moistened. Orange-colored lichen prefer nitrogen rich locations. Some lichens fluoresce in UV light.

Most lichen grow very slowly. They contribute to soil formation. Although generally inedible, some lichens have been used as medicines, traditional dyes, and food sources (reindeer lichen). Some “old-growth” lichen species thrive in very clean air, like on Mt. Tamalpais. Others tolerate more polluted cities. Monitoring of lichen species and growth can inform us about air quality and climate change.

Ann Elliott

20260227 Estero American Coastal Preserve, hosted by Milo Baker Chapter

The February field trip with the Milo Baker CNPS to the newly-opened Estero Americano Coastal Preserve was a fabulous and rare opportunity to experience the beauty of the fjord-like tidal estuary and grasslands.  The field trip was led by Corby Hines, a ranger with the Wildlands Conservancy. The Wildlands Conservancy purchased the 547 acres to protect critical tidal estuary that supports endangered species. They offer hikes through the Jenner Headlands Interpretive Program, and the preserve is open daily.

Even though it was early in the wildflower season at the Estero Americano, we were treated to some gorgeous and colorful early bloomers, including Douglas iris (Iris douglasiana), sun cups (Taraxia ovata), early blue violet (Viola adunca), California poppy (Eschscholzia californica var. maritima), Pacific sanicle (Sanicula crassicaulis), death camas (Toxicoscordion fremontii), common lomatium/spring gold (Lomatium utriculatum) and Tolmei’s pussy ears (Calochortus tolmiei).  At the top of the Ridge Trail, we took in the striking panoramic views of the estuary, surrounding verdant green hills and the Bodega Bay coastline, where the waters of the estuary empty into the Pacific Ocean.

Anna Gil