A Few Examples of Plants and Lichens on Red Rock Hill, San Francisco

By: Emil Fogarino


Fremontia or flannel bush

General Biology: Fremontodendron californicum or Fremontia…..California Flannel bush; 3 species in North America along with hybrids; the plant body lacks petals and instead has 5 bright yellow webbed bracts (sometimes called terrestrial starfish); flowers mainly May to June; Is a Native to California; has fuzzy hairs on leaves that can be irritating to skin and eyes; can grow up to 20 feet tall.


Ecology: Likes full sun and well drained soil; drought tolerant; it can grow anywhere between sea level and 6000 feet in habitats such as chaparral, oak woodland and pine forest. Pollinators include bees.


Human uses:  Native Americans used bark to make string, rope and baby cradles


Interesting fact: Named after explorer John C. Fremont ( also credited for naming the Golden Gate in the 1840’s )



Two types of lichens; foliose and crustose

Foliose Lichen
Crustose Lichen

The two lichens you see in the pictures might be: 1) A shield lichen a type of foliose lichen  2) A crustose lichen (maybe a goldspeck? Or a candleflame?)


General Biology: Lichens are a symbiotic relationship between fungi and either green algae or cyanobacteria. The fungi is the visible part and the algal component is microscopic.  Lichen are considered to be in the Kingdom Fungi.  The relationship is called mutualism where both organisms benefit since the fungi provides shelter and protection while the algal component provides food.  Lichens exhibit a vast array of beautiful pigments that play a role in protecting them from varying degrees of UV light.  Lichens also play a critical role in soil formation since they secrete acids which help decompose rocks over time. 


Human Interactions: Lichens have various medicinal uses along with being used to make dyes.  Some cultures consider them to have magical properties.


Ecological Items: Lichens thrive where the air is clean and thus can indicate degrees of air pollution.  Some organisms eats types of lichens and birds can use them as nesting materials.



© 2018 Sutro Stewards

Sutro Stewards is a project of the San Francisco Parks Alliance, a 501(c)3 California nonprofit public benefit corporation.