While hiking on the North side of Mount Tamalpais, just off the Fairfax-Bolinas Road, we climbed to a spot called Serpentine Knoll. The plants on this section of the trail were dramatically different from all that had come on the trail leading up to it, so it sent me scurrying to Introduction to California Soils and Plants: Serpentine, Vernal Pools, and other Geobotanical Wonders by Arthur R. Kruckeberg to learn more.
Kruckeberg writes: "It is the look of a serpentine landscape that so strikingly catches the eye, especially so where serpentine vegetation abuts a normal nonserpentine plant cover.... in coast redwood country, a serpentine outcrop may support a thinly stocked stand of Jeffrey pine (Pinus jeffreyi) or knobcone pine (P. attenuata) with an understory of scrub oaks, often huckleberry oak (Quercus vaccinifolia) or the shrub form of tanbark-oak (Lithocarpus densiflorus var. echinoides)." Although I didn't have the book with me at the time, my guess is that I was surrounded by huckleberry oak (Quercus vaccinifolia). Additionally, I discovered spots of late wildflowers--perhaps Brewer's clarkia (Clarkia breweri)? In any case, I'm looking forward to reading more about what Kruckeberg calls "the kooky soils-flora story."
Although Serpentine Knoll was not the most beautiful part of the hike (Cataract to Helen Markt to Kent to Serpentine Knoll), it was certainly unusual and intriguing.
Photo by Arthur R. Kruckeberg of huckleberry oak (Quercus vaccinifolia). From Introduction to California Soils and Plants.