Date: April 16th, 2023

Location: Mount Tamalpais at Laurel Dell

Coordinates: 37.9038148 (North), -122.5960903 (West)

Description: Located in Marin County close to the coast of the Pacific Ocean, long windy roads lead us up steep hills that overlook beautiful valleys. The habitat that surrounds Mt. Tamalpais includes hillsides covered in redwood forests, oak woodlands, open grasslands, and chaparral. Many dominant species call Mt. Tamalpais their home including black-tailed deers, mountain lions, coyotes, and foxes.

Plant Descriptions and Images: 

Family: Lauraceae, Genus & Species: Umbellularia californica (California Bay)

This species is a perennial evergreen tree/shrub characterized by woody features with a lighter tan colored trunk. Since it is the only species in its genus, it is easier to pick out with its thick leathery dark green leaves that are a lighter green on the underside. Its leaves can also be characterized as simple, pinnate and alternate with an entire margin, a shape that is narrowly ovate to oblong (appears as a lance), and glabrous (no trichomes) that can make it appear to be shiny. When the tree flowers, its inflorescence is umble-like with flowers appearing on the upper axils. These flowers are smaller, creamy white in color and form clusters. It is important to note that the leaves of the California Bay are very aromatic, especially when torn or crushed.

Family: Blechnaceae, Genus & Species: Woodwardia fimbriata (Chain fern)

This species is a perennial evergreen herb characterized by short stature and rhizome prostrates. Since its a species of fern, it has similar morphology to the other families such as having compound pinnate leaves that sprout from the same origin in the ground. However, that is where most similarities end. Chain ferns have bipinnate leaves that are coarse with large scales that make them appear less delicate than the smaller ferns. Each leaf is generally 1 – 3 meters with pinnae that are 15 – 30 centimeters in length. The pinnae are connected in a way that make the the leaves look lobed and are often glandular with microscopic trichomes. These ferns range from green to orange-brown in color and can be up to 8 feet in length. A chain of sori on the underside of the leaves give the plant its common name.

Family: Fagaceae, Genus & Species: Notholithocarpus densiflorus (Tanoak)

This species is an early-deciduous, perennial evergreen tree/shrub characterized by woody features with broad leaves and a reddish-brown to gray-brown trunk. The bark is moderately thick with furrows and ridges. Since it is the only species in its genus native to North America, it may be easier to pick out due to its thick, leathery, light green leaves and its ability to produce acorns. However, it is not a true oak even though it’s commonly known as Tanoak and it produces a similar fruit. Its leaves are simple, alternate, and generally glabrous with an entire to serrate margin. The shape of the leaves are oblong to ovate with a round base and obtuse tip. Flowers are separated into male and female inflorescences. Male inflorescences are catkins in a spike formation that are erect, dense in flowering, and are white to rust-colored. The female inflorescences are found below the males either on the same or a separate stalk with one flower. It is important to note that many of the Tanoaks seen were infected with a disease called Sudden Oak Death.

iNaturalist Submissions:

1. https://www.inaturalist.org/observations/163553739
2. https://www.inaturalist.org/observations/163554106
3. https://www.inaturalist.org/observations/163554521

Narrative:

It was a beautiful spring day when my dad and I took a trip up to Mount Tamalpais to find some new species of plants. The drive to the site was long, but it was worth it to get some fresh air and explore new scenery. When walking down the hill to Laurel Dell, I was able to spot many of the new species right away. It felt empowering to know that I am able to identify the plant species as quickly as I did. My dad was also trying to find the different plant species with a plant identifying app other than seek, which was amusing to me. As we continued deeper into the wooded area, it started to get colder and windier, which made trying to find the plants less pleasant. However, it was beautiful to see all the creeks and other natural life on the Mountain. We weren’t able to find as many plant species as I would when going on a field trip with the class, but it was a fun experience and great practice overall.