Carnivorous Plants of the Smith River Region ~ Stoney Creek Trail
In the hinterland of northwest California, the Smith River’s crystal blue waters drain abruptly from the Siskiyou Mountains toward the Pacific Ocean—along the way gouging out sparkling canyons through ancient serpentine rock. High levels of precipitation coupled with serpentine geology have fostered unique plant communities in this region. Because the serpentines soils of the Josephine Ophiolite are rich in heavy metals the ecosystem appears infertile. Seemingly sparse red-rock forests endure in stark contrast to the lush redwood forests of the North Coast Range only a few miles away. But upon closer inspection, the red-rock nurtures plant communities that are species rich and teeming with life.
Serpentine outcrops are fortified with heavy metals, which restrict a plant’s ability to grow. Certain plants, however, have adapted to this medium and flourish with the reduced competition from other plants. Over millions of years this geographic isolation has been responsible for the speciation of a remarkable number of rare plants. John Sawyer has recorded 200 neoendemic plants on the serpentine outcrops of northwest California. On the Josephine Ophiolite alone, there are 70 endemic species—more than any other serpentine outcrop in North America. Because most plants have evolved on "nutrient balanced" soils for millions of years, these serpentine substrates pose a problem. While some important elements such as nitrogen, potassium, and phosphorous exist at low levels in serpentine, other toxic elements exist at very high levels. These elements often inhibit plants from performing various metabolic functions; for example, high levels of magnesium restrict a plant’s uptake of calcium. Plants that survive on porous serpentine are also slow-growing and therefore dwarfed in size compared to relatives on nutrient rich soil. Evolving on these restrictive sites, plants have become both geographically and reproductively isolated from an ancient parent populations.
Three plant—butterwort, Darlingtonia, and sundew—have successfully undertaken survival on this harsh rocky purchase. By absorbing digested nutrients from insects they lure and capture these plants have found a dietary supplement; overcoming the lack of nutrients offered by the rock. Two of these carnivorous plants can be found along the Stoney Creek Trail in the Smith River National Recreation Area.
Horned Butterwort (Pinguicula macroceras ssp. nortensis)
Horned butterwort is classified by the California Native Plant Society as a List 2 species—it is rare, threatened, or endangered in California but common elsewhere. In the state it has only been recorded in Del Norte, Siskiyou, and Shasta Counties for a total of 34 observations on Calflora.
The striking flower of P. macrocerus.
Sticky leaves trap, roll over, and slowly digest the nourishing insects—supplementing the nutrient poor soils on which these plants grow.
California pitcher plant (Darlingtonia californica)
This insectivorous species is one of ten in the relict family Sarraceniaceae, and the only member of its genus that still survives on Earth. Northwest California is a refuge for this species; here it survives as a hold-out of the ancient Tertiary forests that dominated the northern hemisphere millions of years ago. The cobra lily also supplements its diet by trapping insects but this species entices them inside the stem where its victims endure a slow death—by incarceration. Instead of its leaves or stems producing an enzyme to deal with digestion, the pitcher plant harbors bacteria and protozoa inside its "pitcher." In a symbiotic relationship, the digestion is done by microbes and nutrients are shared. This species is restricted to fens, which are spring fed wetlands. It is often incorrectly stated that pitcher plants live in bogs—a rare habitat in California which consists of standing water and an accumulations of acidic peat.
The mysterious pollinator of Darlingtonia is currently unknown.
Stoney Creek Trail-Smith River National Recreation Area
From the town of Gasquet, Ca—along Highway 199 in Del Norte County—travel north on Gasquet Flat Road, take a quick right and in about half a mile a left on Gasquet Middle Fork Road which you can take to the end. There is limited parking and the hike is short. Enjoy the botanical wonders of the Smith River Region.
Along Little Stoney Creek Darlingtonia and Pinguicula grow side by side.
- Barry Rice "The Carnivorous Plant FAQ" accessed 4-15-2009
- Bob Zeimer "Carnivorous Plants of the Smith River Near Gasquet" Accessed 4-15-2009
- Sawyer, John O. (2006). Northwest California. Berkeley, CA: University of California Press