Carnivorous Plants of the Smith River Region ~ Stoney Creek Trail

Original Publication DATE: 4/18/2009 2:37:00 PM

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)
This species has spotty distribution across western North America. In northwest California, it is restricted to serpentine soils where it often grows on steep rocks or fissures in rocks that often receive little or no direct sunlight. Another habitat requirement is the presence of water—whether from seeps or close proximity to splashing water—pinguicula’s root must remain wet. The sticky light green leaves entice thirsty insects in for a visit with their wet appearance. The glands on the upper surface of the leaves initially trap the insect, on contact glands release more secretions, trapping the insect further, with more struggles, more stickiness, and the critter’s fate is sealed—ensnared in sticky mucilage. Once the insect is trapped the leaves slowly curl over the carcass and release digestive enzymes to break down the “tasty” parts. Finally, the leaf absorbs those nutrients through cuticular holes in the plant and incorporates them into the photosynthetic process.

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.

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.

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.

• Plant List from the Humboldt State Herbarium

Resources:

1. Barry Rice “The Carnivorous Plant FAQ” accessed 4-15-2009
2. Bob Zeimer “Carnivorous Plants of the Smith River Near Gasquet” Accessed 4-15-2009
3. Sawyer, John O. (2006). Northwest California. Berkeley, CA: University of California Press

COMMENT:
AUTHOR: Dr. Hawk
DATE: 10/12/2009 1:11:48 PM
Mike,

Stumbled into your blog and wanted to say kudos for your excellent reportage on these sites. I have been into both of these areas because of my research on carnivorous plants* and orchids over the past 20+ years in the western US.

Your report on the Stoney Creek area is curious as even most cp folks never go there because it is just so obscure compared to so many other cp sites in the cp capital of CA–Gasquet.

Did you know that Youngs Valley also has Darlingtonia (scatterred), Pinguicula (Cracker Meadow, Raspberry Lake), and Drosera (reported, but not seen)? Have you seen these species thereabouts? I have always come into the Valley from the west, have you tried any other approaches?

Dr Hawk

*Carnivorous Plants of the West, Vol II: CA, OR,WA. 1995