Location: San Pedro Valley Park – Trout Farm Trail; Northern edge of Santa Cruz mountain range
Site Description: Open trail surrounded by very dense forests. Weather was cold with a lot of moisture in the air. Stream running through beginning of the trail and along parts of the trail due to heavy rain earlier in the week. Dominant species at the beginning of the trail include young California redwoods (Sequoia sempervirens), species from the genus Quercus (oaks), and redosier dogwood (Cornus sericea). Further along the trail, we ran into some manzanitas which dominated a large portion of the top of the trail. Their exact species was undecided, but they shared very similar morphological characteristics, both were believed to belong to Arctostaphylos sp.. Along the trail and deading down the trail, one of the most prominent species that we saw many Eucalyptus trees which I will discuss more later in the blog post.
We departed USF around 1:00pm to avoid rainy conditions. Upon arriving to San Pedro Valley, we parked and met at the beginning of the Trout Farm Trail.
The first species we identified was the redosier dogwood, a member of the family Cornaceae. This shrub had opposite node arrangement with pinnately venated leaves. Dogwoods, in general, are found near water and are often planted outside of houses for aesthetic purposes. The leaves were fairly large with an acuminate apex and a pubescent underside. The most noticeable characteristic about the redosier dogwood was its red stems leading up to the leaves and the white umbel inflorescences. Another cool fact about their leaves was that once ripped apart, the hairs on the underside of the leaves kept the separated leaf parts together.
Continuing on, we saw a very familiar species – the Trillium ovatum. We also saw the giant wakerobin (Trillium chloropetalum [pictured above]), which is related to and looks very similar to the trillium ovatum. The major difference is that it is larger, has petals with a pink-ish tint, and weak mottling on its leaves.
An unfamiliar tree that we ran into was the Coast live oak in the genus Quercus and the family Fagaceae. It had many lichens and mosses living on it and its branches create a canopy-like structure that covered a fairly wide area. Shortly after, we ran into a familiar tree: the Arroyo willow. Its catkins were still fairly active with many male plants having pollen that could be flicked loose.
One flower that we saw during our hike was the greater periwinkle (Vinca major). This bisexual flower has 5 purple petals that are fused at the base; the flower’s shape reminds me of a windmill. The sepals of the periwinkle, which are claw-like and green, are vastly different from their petals. It is an invasive species that usually resides in tropical climates. It belongs to the family Apocynaceae, which are known widely to be tropical flowers. Its leaves have opposite nodes, a somewhat chordate base, and contain a white fluid on the inside that is known as a latex.
Near the top of the trail, we ran into a Manzanita forest where two members of the Ericaceae family dominated the rough soil. They have white bell-shaped flowers that occur in cluster-like inflorescences. The inflorescences pictures are fairly young. Their stems are pubescent, but their brittle leaves with slight dentation are glabrous. Their most recognizable characteristic, aside from their flowers, was their peeling bark to reveal red wood underneath. The specimens pictured are most likely an Arctostaphylus sp..
Eucalyptus trees dominated the entire trail. Aside from the manzanita forest near the top of the trail, eucalyptus trees were found almost everywhere throughout the trail. Originating from Africa, these invasive trees grow very fast when given access to large quantities of water. Their sword-like, sickle-shaped leaves are a unique characteristic to adult eucalyptus trees, while young trees exhibit blue-green stems and more traditionally pinnate-shaped leaves. These trees grow very tall and incidentally provide a lot of shade which limits sunlight for other plants and leaves room for understory adapted plants to grow. On our way back to the cars, along the Brooks Creek Trail, we saw many eucalyptus trees-all of which are believed to be blue-gum eucalyptus (Eucalyptus globulus).
Summary – This trip to San Pedro Valley introduced us to some really cool species, as well as a couple of species that we’ve seen on previous field trips. It was great to get a review through recognizing some Trilium’s, Arroyo willows, Sagebrush, etc.. We also saw some familar familes: Asreraceae, Boraginaceae, Fagaceae, and others. One of the more surprising things to me was how dense this forest was. Most of the sites we’ve been to have been pretty open with mostly shrubs acting as the major ‘canopy’. Additionally, I was surprised to see so many invasive species in the area.
California buckeye (and acorn)