I “discovered” Pulgas Ridge Open Space Preserve four years ago, and I have now visited each year during the spring or early spring. Of course, the timing and abundance of wildflowers depend on several factors, including the timing and abundance of rain, as well as the month. My first two visits were in 2014 and 2015, both in May. In 2017 I visited in April. These two hikes (2016 and 2018) took place in early February and were focused on early spring wildflowers.
Pulgas Ridge is one of 26 open space preserves managed by the Midpeninsula Regional Open Space District, often called Midpen. Pulgas Ridge is one of the smaller preserves, at 366 acres, and is located in San Mateo County near the city of San Carlos. One of its special attractions is an off-leash dog area in the center of the preserve, and leashed dogs are permitted on all other trails. Even if you take trails that do not intersect the off-leash area, as I did, you will most likely encounter hikers with dogs at some point during your visit. All of the dogs I’ve encountered at Pulgas Ridge have been very well-behaved and under proper control of their owners. The preserve used to house a tuberculosis treatment center; all of the buildings were demolished after Midpen acquired the property. I have not been able to discover the origin of the name Pulgas Ridge, though pulgas means fleas in Spanish.
This post primarily describes my 2018 visit, but my 2016 visit followed an almost identical route. And both visits were motivated by a desire to see an early spring wildflower with the unusual common name of fetid adder’s tongue (Scoliopus bigelovii). Apparently the blossoms are considered to be foul-smelling, though you have to get down close to them – the plants are typically less than 6” tall – in order to smell them. And I think adder’s tongue refers to the shape of the underground part of the plant.
In any case, seeing the fetid adder’s tongue was the highlight of both hikes. The foliage is quite distinctive: two broad leaves that are typically mottled with brownish spots. The blossoms are fairly intricate, though are often noticed by people only after seeing the foliage. In fact, the showiest part of the flower, with a light background color and delicate purple-brown veins, is actually the sepals rather than the petals.
The route for my hike was basically a semi-loop with a short extension. On the map the orange dot shows the main parking area. From there the Blue Oaks Trail switchbacks uphill to the beginning of the loop. Since I was planning to skip the off-leash dog area, I hiked clockwise around a loop consisting of the Dick Bishop, Polly Geraci, and Hassler Trails before descending the Blue Oaks Trail. Near the bottom end of the Polly Geraci Trail I took a short extension on the Dusky-Footed Woodrat Trail. The entire route was about 3.1 miles.
The elevation gain and loss are moderate, about 550 feet total, so the average grade is about 6.7%. The highest point, a bit under 750 feet elevation, is the junction of the Dick Bishop and Polly Geraci Trails. Near the end of the loop the Hassler Trail climbs up to the Blue Oaks Trail. An alternative route, which I took in 2016, essentially follows Hassler Rd (visible on the GPS track map) back to the parking area and is level.
The first part of the hike is the climb up 0.4 mile long Blue Oaks Trail, which makes a few switchbacks through a lovely blue oak forest area dominated by shade. This year the area is dry due to low rainfall levels, but it was somewhat moister in 2016. On that hike there was quite a bit of Indian warrior (Pedicularis densiflora) in areas that received partial sun, though on this hike I didn’t see any at all.
There were also several Henderson’s shooting stars (Primula hendersonii). This particular plant was evidently getting ready to launch several more blossoms.
Another shade-tolerant early bloomer is Pacific hound’s tongue (Cynoglossum grande). This plant was also getting ready to produce additional blossoms.
In addition, there was miner’s lettuce, Bermuda buttercup, and – of course – poison oak.
Closer to the top of Blue Oaks Trail there are some chaparral plants, including manzanita (Arctostaphylos sp.). Manzanitas come in a variety of sizes – this one was what I consider to be a typical size, about 5 ft tall – but I have not yet learned to distinguish them at the species level. Later, along the Polly Geraci Trail, I would see perhaps a different species, with a slightly pinkish tinge to the blossoms.
At the top of Blue Oaks Trail there are a few different trail options, and I turned left on the Dick Bishop Trail, which continues to climb, gaining about 200 feet in 0.7 mile. Along the way there is a nice view of Edgewood Park and Natural Preserve, which is located just across Edgewood Rd from Pulgas Ridge. Edgewood, a San Mateo County park, is well-known for wildflowers.
The trail passes a colorful silver wattle (Acacia dealbata), sometimes called mimosa tree. The bright yellow flowers are like small balls about 1/2 inch in diameter. Unfortunately, this is a non-native tree.
I was particularly impressed by one particular oak tree along the Dick Bishop Trail. I suppose it is a coast live oak (Quercus agrifolia) since that is the most common evergreen oak in the area. However, coast live oak’s leaf edges are supposed to be spinose (spiny-toothed), and this tree’s leaf edges were smooth-looking. In any case, it was not a blue oak (Q. douglasii) since blue oaks are deciduous.
Along the Dick Bishop trail I also saw some pre-blooming wavy-leaved soap plant (Chlorogalum pomeridianum), which is easy to identify from its characteristic long, wavy leaves.
The top end of the Dick Bishop Trail leads directly, crossing paved Hassler Trail, to the Polly Geraci Trail. The upper portion of the trail travels through chaparral, including manzanita and toyon (Heteromeles arbutifolia) among other species. Toyon is notable for its bright orange-red berry clusters.
The lower half of Polly Geraci Trail is shaded and generally moist, though less moist than usual this year (2018). A variety of ferns can be found, including several bright green species and a dark green species. One of the more interesting, as well as distinctive, ferns is maidenhair fern (Adiantum jordanii).
Another early spring wildflower is milk maid (Cardamine californica), with four delicately veined white petals. It is found in many different types of plant community, but generally along stream banks or on slopes. These were in the lower, moist and shaded, section of the Polly Geraci Trail.
In 2016 I encountered a couple of plant experts who pointed out an unusual plant in a particularly moist slope area next to the trail. If I remember correctly, it is called a liverwort, which is a type of non-vascular land plant. They are most similar to mosses.
In 2016 I saw a few California buttercups (Raununculus californicus) along the Polly Geraci Trail. My 2018 hike may have been too early for them to be blooming.
A trail junction near the lower end of the Polly Geraci Trail provides access to the Dusky-Footed Woodrat Trail. Although this trail climbs back up into the chaparral, on this hike I only covered about 0.2 mile, in a shady forest area next to Cordilleras Creek. Along both trails I encountered some common snowberry (Symphoricarpus albus) shrubs in shady and moist areas. Snowberry is deciduous, so its pure white berry clusters on bare branches are rather easy to identify in the winter and early spring. (The leaves in the background of the picture belong to different plants.)
One of my favorite early spring flowers is trillium, and there are a few species that are found in the Bay Area and in San Mateo County. On my 2016 hike, but not on my 2018 hike, I found numerous common, or giant, trilliums (Trillium chloropelatum) on the Dusky-Footed Woodrat Trail near the junction with the Polly Geraci Trail. These spectacular plants thrive in shady forest areas and often grow in clumps. An interesting footnote, which perhaps explains the clumping growth habit, is that trillium seeds are dispersed by ants. Another interesting fact is that the large leaf-like structures, which do perform photosynthesis, are actually bracts; trilliums do not have leaves!
Along the first part of the Dusky-Footed Woodrat Trail there are a couple of tree stumps that always seem to sport colorful fungi. This is a collection of brownish turkey tail (Trametes versicolor) which is actually a type of mushroom.
About 0.2 mile from the Polly Geraci Trail there is a bridge that crosses Cordilleras Creek. From the picture it is obvious that it is a simple bridge, but it conveniently marks a location along the trail.
The importance of this location is that there is a “colony” of fetid adder’s tongue (Scoliopus bigelovii) growing between the creek and the trail about 10-15 yards before the bridge. This makes it really easy to return to the same spot, without needing to use GPS coordinates or even look very hard, to find the plants. Here is one example; the stem extends well above the leaves.
And here is one more example, in which a single plant has produced three blossoms at the same time. (I admit that, when I find a special wildflower, I usually take at least a dozen photos, sometimes more!)
It should be noted that the leaves last several weeks longer than the blossoms. In fact, I have a couple of photos from my May 2014 visit that, in retrospect, are of fetid adder’s tongue leaves. I had no idea at the time about the flower, since it was absent – I just thought the leaves looked interesting!
It is always a joy to visit an open space that has a reputation for excellent wildflowers, because there is typically a good variety. Later in the spring the early flowers are replaced by later blooms, such as yellow sticky monkeyflower, blue dicks, yerba Buena, blue-eyed grass, and yellow mariposa lilies, among others.