Bay Nature magazineSpring 2001


Of Hazelnuts and Adder’s Tongue

April 1, 2001

The bobcat seems frozen in space. A Botta’s pocket gopher, oblivious, partially emerges from its burrow to nibble on some tender grass shoots. The bobcat pounces. A red-tailed hawk lets out a piercing cry. Energy flows. Matter cycles. It is early morning along Weiler Ranch Road in the 1,295-acre San Pedro Valley County Park and already there are a few walkers, joggers, and bicyclists on the go. I’m heading toward an eastern launch point onto the Hazelnut Trail, one of my favorite strolls on Montara Mountain. Montara Mountain is a sleeper as landmarks go, within view of San Francisco. It doesn’t stand out like Mount Diablo or Mount Tamalpais. And yet it is a major peak easily accessible from this metropolitan area. It is also full of wildness and peaceful vistas that stretch as far as the eye can see. The summit of Montara Mountain—actually an assemblage of three summits—is a rugged granite highland terminating a 10-mile ridge that reaches south to Half Moon Bay. At Devil’s Slide and Pedro Point, it plunges into the sea like a great ocean liner. Granite cliffs and slopes drop from almost 2,000 feet to sea level in less than three miles.

Unlike interior slopes farther south in the Santa Cruz Mountains, scrub rather than conifer forest dominates these uplands. Indeed, the only tall forests in this area today are those recently introduced by people: stands of eucalyptus, Monterey pine, and Monterey cypress. Otherwise, as chronicled by Spanish explorers as early as 1769, the slopes and ridges surrounding Montara Mountain appear smooth and undulate from a distance. Once, much of the San Francisco Peninsula—from Montara Mountain north to the Golden Gate—looked this way, the landscape shaped by frequent fog, salt spray, and cold winds. Only six miles across, this island-like San Francisco Peninsula is a “hot spot” for endemics (species that are found only in one area) and unusual natural communities, and has thus been deemed a distinctive bio-geographic unit, the “Franciscan Landscape.” Urbanization of the peninsula has left little of this remarkable biota intact, but here, in the valleys and ridges that surround Montara Mountain, it is alive and humming. Montara Mountain . . . Franciscan refuge.

Weiler Ranch Road follows the valley of the middle fork of San Pedro Creek. The trail provides a good vantage for viewing the extraordinary mosaic of scrub plant communities that dominate this landscape. These communities are largely organized by the slope and aspect of surrounding ridges, as well as by rock substrate and soil depth. South-facing slopes are dry, while north-facing slopes are moist. Deeper soils are dominated by semi-deciduous or deciduous scrub (coastal scrub), while shallow, rocky soils are dominated by evergreen scrub (chaparral). Scrub is typically a vegetation type that “gets no respect,” and yet ecological studies have demonstrated that scrub communities often support a greater abundance and diversity of animals than adjacent forests or grasslands. This is because scrub plant species produce rich crops of flowers, nectar, and fruit while providing excellent protective cover and breeding habitat for insects, birds, reptiles, and mammals.

Adder's tongue
Fetid adder’s tongue. Photo by Michael Vasey

The common component for the scrub assemblages surrounding San Pedro Valley is coyote brush, which is sometimes dominant, sometimes sparse, but almost always present. Coyote brush is an example of a species derived from a perennial herbaceous ancestor (in this case, within the sunflower family) that has most likely become “woody” secondarily. It frequently associates with other species that have also derived from former perennial herbs, such as lizard tail, California sagebrush, sticky monkey flower, and yerba santa. These species have semi-deciduous “soft” leaves, losing many—but not all—of their leaves during the dry season. Their wood anatomy does not have characteristic rings of vascular tissue like primary woody species.

Generally, the coastal scrub covering south-facing slopes picks up the gray-green hue of California sagebrush, which here shares dominance with the coyote brush. Merging subtly with this gray-green coastal scrub is a more mixed, semi-moist coastal scrub in which a number of evergreen species—such as toyon, blue blossom, coffee berry, and silk tassel—join the dominant coyote brush. This semi-moist coastal scrub is the most widespread vegetation in the area, and can be found all the way around and up onto the higher summits of Montara Mountain. It is the matrix vegetation from which the other kinds of scrub emerge.

In contrast to the coastal scrub, vegetation dominated by species that have primary woody anatomy and “hard,” evergreen leaves is called chaparral. While chaparral is most widespread in the interior ranges of California, a variant, often called “maritime chaparral,” is found here in the fog zone of the California coast. Fog drip is a key to the rich diversity of species on Montara Mountain, most likely providing up to one-third of the annual available moisture in this ecosystem and keeping the cool, clear forks of San Pedro Creek running all year. Gazing up toward the summit, you’ll see dark green islands of maritime chaparral flowing down the ridge crests into the valley. Manzanita is a typical chaparral resident, and this chaparral hosts two species: the brittle leaf manzanita and the locally endemic Montara manzanita. Joining these are the golden chinquapin and the California huckleberry. Occasional madrone trees punctuate the margins of these dense stands.

Surrounding these islands of chaparral is yet another kind of coastal scrub, a fully-moist scrub that is dominated by two completely deciduous species: California hazelnut and cream bush. In the winter, their pale gray and brown lichen-encrusted branches create a ghostly wash over north- and east-facing slopes. While the coyote brush-dominant coastal scrub is found in many other areas along the central California coast, this hazelnut-cream bush assemblage is virtually unique to Montara Mountain. The Hazelnut Trail, a 3.7-mile semi-loop, is one of the best ways to experience the special charms of this unusual vegetation.

You’ll find the start of the Hazelnut Trail near the end of Weiler Ranch Road. As you start up the trail, look first for western burning bush, a deciduous shrub with small, five-petaled, brownish-purple flowers that typically bloom in early spring. After flower season, look for branches bearing opposite, deltoid leaves bearing fine serrations on their edges. In the fall, after losing its leaves, the shrub sports gaudy orange and purple fruit. Normally found along streams in forest environments, burning bush’s presence in this scrub vegetation is the first hint of the botanical anomalies encountered along the Hazelnut Trail.

Hazelnut bush in late summer. Photo by Michael Vasey

As the trail climbs, California hazelnut becomes the most common species in the scrub. In winter, its golden male catkins and tiny scarlet female flowers dangle among a lattice of straight, gray branches. In the summer, the shrubs are covered by a profusion of felt-like, pale green leaves; be sure to rub the leaves gently between your fingers! By late summer and early fall, particularly in good years, large numbers of hazelnut fruits cluster together in their fuzzy reddish jackets. As these split apart, the rich brown hazelnut fruits show through, signaling their ripeness. Generally, though, the nuts don’t last long, as squirrels, jays, and numerous other species snap them up. Undoubtedly, hazelnuts were also a favorite food of the grizzly bears who roamed San Pedro Valley in times past.

The most common associate of the hazelnut on Montara Mountain is the cream bush, a shrub in the rose family. In the late spring and early summer, cream bush sends out great plumes of small, cream-colored flowers, accounting for its other common name, ocean spray. The aromatic pitcher sage, Franciscan paint brush, coyote mint, and milkwort are other wildflowers that enliven the Hazelnut Trail in late spring and early summer.

Earlier in the year, from late January through February, another special feature of the hazelnut-cream bush scrub goes on display. Before these deciduous shrubs leaf out, a rich profusion of wildflowers in the lily family comes into bloom in the filtered light and dark humus beneath the scrub canopy. Wake robins, giant trillium, slender false solomon’s seal, and fetid adder’s tongue blossom between clustered stems of shrubs and clumps of sword fern. Fetid adder’s tongue—with its mottled green leaves, brown-purple striped flowers, and odor of rotting flesh—is particularly abundant. The odd thing is, these species normally grow in the shady understory of redwood and Douglas fir forests, making this entire assemblage seem completely out of place on this open hillside. Here we encounter one of those puzzling anomalies that makes exploration of Bay Area landscapes such an endless joy.

I offer the following as a speculative hypothesis for this particular phenomenon: When the Spaniards arrived in San Pedro Valley in 1769 and noted the absence of tall trees, a village of Ohlone people was well-established; Native American artifacts from nearby coastal sites demonstrate that people had occupied this area for over 5,000 years. During that time, sea level rose over 300 feet and moved in steadily from several miles offshore, the Bay formed, and the climate of the northern San Francisco Peninsula became progressively more maritime. My guess is that San Pedro Valley once hosted a conifer forest, but the conifers could not tolerate the increasingly maritime conditions (especially the salt spray). The introduction of a frequent burning regime by local Native Americans (seeking to encourage the growth of desirable plants) may have added stress to the conifers. Although Douglas fir eventually disappeared, some of the understory species—such as hazelnut, western burning bush, trilliums, and fetid adder’s tongue—were left behind. These more salt spray- and fire-tolerant species managed to persist until the present as our special hazelnut-cream bush scrub.

Back on the Hazelnut Trail, the mosaic of hazelnut-cream bush scrub, maritime chaparral, and coyote brush scrub accompanies you as you wind farther up the ridge. At last, the trail flattens, and a park bench invites a breather after the long climb. From here, there are great views of San Pedro Valley and the ocean beyond, Sweeney Ridge to the north, and the plunging, foggy, dark green slopes of Montara Mountain to the south. The trail begins to wind its way downhill to the visitor center. Those wishing to continue up to the summit now encounter one drawback of the Hazelnut Trail: You can’t get there from here. You will have to head back down, then take the Montara Mountain Trail up from the parking area.On the way down, the trail cuts through good stands of maritime chaparral. When the manzanita blooms, it is loaded with nectar and attracts insects and hummingbirds. Swarms of insects visit its bursting inflorescences, and small passerine birds—such as chestnut-backed chickadees, Townsend’s warblers, and Bewick’s wrens—forage for insects in the manzanita canopy. Meanwhile, the rustling you hear in the scrub is most likely a wrentit, a small grayish-brown bird heard more than seen in scrub and chapparal habitats. By now, the different variations of scrub are becoming familiar and almost comfortable. It is the downhill stretch and aromatic scents and bird-songs fill the air.

Ben Pease

Time is the dimension that ties together the web of life. A bobcat moment, the blooming of a trillium, or the gradual emergence of a unique form of scrub; each is a function of history, that symphony of dynamic processes and patterns transpiring at different scales. And each is on view here on the slopes of Montara Mountain. After traveling the Hazelnut Trail, you’ve only just begun to experience the special qualities of this place.

Getting there:

By bus: Samtrans route #110 from Daly City BART, or route #112 from Colma BART, to Linda Mar Park and Ride in Pacifica. Transfer to route #14 and ride to corner of Oddstad and Linda Mar boulevards. Walk one block south on Oddstad to Rosita; turn left into County Park. For schedules and maps:, or (800)660-4287 (Mon.-Fri. 6 a.m.-10 p.m., weekends 8 a.m.-8 p.m.).

By car: Route 1 to Linda Mar Blvd. in Pacifica; east on Linda Mar to Oddstad Blvd.; right on Oddstad to Rosita, then immediate left into County Park. San Pedro Valley County Park is open daily. The visitors’ center is open on weekends. For information, call (650)355-8289.

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