A stony hillside is awash in a sea of color. Swatches of yellow, purple, and pink nearly obscure the barren slope, which (other than the flowers) is striking because of how little grows there. This is a serpentine outcrop, and the harsh chemistry of this rock prevents all but a few hardy and specially adapted species from growing.
One lovely serpentine-dominated outcrop is perched atop Mt. Tamalpais near the Rock Springs parking area, and is in full and glorious bloom right now. I’ll write about each of the different species over the next few days–but the above slideshow celebrates the panorama.
Amazingly, there are even more surprises waiting on the stony hillside. Later in the season other flowers, including buckwheat, Mt. Tamalpais jewelflower and yellow mariposa lily, will appear. But for now there is no sign of them.
Growing across a rocky bed of serpentine is a field of low white flowers. Look close, and you see that the leaves and stems are sticky and thick with white hairs. Nestled among the hairs are little dark dots that are actually glands. This is what makes it sticky – and also the source of the name, Calycadenia multiglandulosa.
You’ll usually see this little plant on serpentine, and only in California.
The views are amazing on this high rocky ridge, and so are the plants. Dense stands of chaparral suddenly open onto stony serpentine outcrops supporting those hardy plants that can survive on such nutrient-poor soils. Right now ceanothus and manzanita are in bloom, and there are scattered meadows filled with wildflowers – goldfields, poppies, lupine, falselupine, and many more.
Get to Pine Mountain by driving up Bolinas-Fairfax road. The ridge runs northwest from a big turnout – you can walk all the way in to the San Geronimo Valley from here, on a wonderful network of trails and through a lovely rare forest of dwarfed Sargent cypress. There are no roads or houses in this area, and so as you walk often all you see is a tangle of forested ridges and valleys. And when you turn around and head home, you get sweeping views of the bay, the Richmond bridge, and Mt. Tam!