Small Things in Redwoods

Five-petaled nodding flowers of the white-veined wintergreen.   

Coast redwood trees get lots of attention and adoration. Yes, redwood trees are big, ancient and have interesting forms and adaptations. Even so, all this redwood worship sometimes makes me squirm because the oak woodlands, coastal prairies, serpentine meadows and many other and richer vegetation types of California deserve equal attention and protection. It's an ecologist's point of view which sometimes makes me unpopular. As if to rebuke my profanity, recently I stumbled onto a small natural marvel in a forest of redwood giants.

A banana slug plows through deep redwood duff.   

Dark redwood forests usually have a low diversity of trees and understory plants. The overlapping canopies of the tall redwood trees shade out smaller plants - and everything is smaller than a redwood tree. Redwoods constantly drop needles, branches, and bark, or even topple over wholesale, so the soil beneath them is covered in a deep acidic layer of organic material which decomposes slowly and hinders seedlings from snagging even an errant spot of sunlight.

Redwoods also get competitive underground. Their shallow and pervasive roots lock down soil real estate. Along streams, redwoods are kings because after floods the newly laid silt rearranges the soil-air balance and suffocates the roots of most plants while any tossed redwood with even a small buried corner will send new feeder roots upwards and thrive. Redwood bark is hard to burn and insulates the underlying living wood from flames, whereas other trees and shrubs of the wet coastal forests succumb to occasional wildfires. After a timber harvest, coast redwood trees readily sprout new growth from the roots of the felled trees and will grow faster than most other woody plants to reclaim a cut and graded landscape.

A sword fern finds enough light under the redwood canopy.
The redwood trunk on the left lives on despite the old and large fire scar that carved out a third of its circumference.      

So when I see an unusual shape or color on the floor of a redwood forest, I stop to investigate what has survived underneath the leviathans. The Dipper Ranch is mostly sunny grasslands, but we travel just a few miles to the west to visit the cool redwood forests of the Santa Cruz Mountains on hot summer days or even in the winter to hear the rain patter on thick brown duff.

Flowering spires of the white-veined wintergreen.
This plant had no leaves at its base or along the flowering stem.    

In Portola Redwoods State Park, spires of small white flowers caught my eye on the forest floor. They were hanging from short green stems jutting bare and leafless out of a pile of brown redwood needles. I didn't remember ever seeing this simple plant in the Santa Cruz Mountains. The overall plant form reminded me of orchids but the flowers were not exotically shaped, just five oval petals with a blush of rose color on their tips. Somewhere in the back of my mind the word "wintergreen" popped up and I remembered finding a small plant in a Kentucky forest that had dark green leaves with bright white etchings. I wasn't sure how that leafy, flowerless plant in Kentucky which I discovered decades ago on a summer walk and this leafless one in California were related, but after years of learning and forgetting thousands of plant names I trust the word echoes in my head as important clues.

I couldn't find the word "wintergreen" in the index of Plants of the San Francisco Bay Region which I carry with me on hikes these days. It was a lazy weekend and I actually had time to push through a plant identification key, so I flipped to the very beginning of the flora. Fortunately, the key to all the herbaceous plants of this nine-county region quickly divided out the plants that don't have leaves. I decided to search through the leafless choices in the heath family, Ericaceae, because the flowers in front of me vaguely resembled those of manzanitas and huckleberries.

Ten anthers crowd into the white-veined wintergreen flower
and the long style curves downward and hangs below the white and rose-tinged petals.   

With fingers splayed across the pages at indefinite yes and no answers, I eventually arrived at whitevein shinleaf (Pyrola picta). The brief notes in the flora indicated this plant has both a green form (presumably that means with leaves) and a nongreen form (leafless?) but its indicated range in this region - Napa and Sonoma Counties and further north - was about 100 miles off from Portola Redwoods State Park. Crouching on a slippery duff-covered slope, I held the flora's sketch of a whitevein shinleaf up to the specimen softly glowing in a small gap of afternoon light. They looked similar but there's so many plants in California, I couldn't be sure. So I did that curious botanist thing: counted and measured parts, especially flower parts, and photographed the plant from all angles. I wouldn't collect any of the plant because I was in a park, it was the only plant of this type around, and if the range description in the flora was correct, it could be rare at this location. As I hiked out of the park, I looked for more small white flowers on the forest floor but saw no others.

A turret spider, another small thing, hides inside the tunnel home it made out of redwood needles.
Turret spiders are found only in moist forests of California (Lukas 2011).  

That night after browsing through CalFlora, CalPhotos and the Jepson Manual, I confirmed that this plant was indeed Pyrola picta but was also called white-veined wintergreen. Ah, the botanical echoes served me once again. The plant distribution map on CalFlora shows other reports of white-veined wintergreen occurring in the Santa Cruz Mountains including ones in Portola Redwoods State Park, Castle Rock State Park, Big Basin Redwoods State Park and El Corte de Madera Open Space Preserve.

Why do some of these wintergreen plants have leaves and some do not? It's because they have a special relationship with fungus and are therefore known as myco-heterotrophs. The roots of the Pyrola wintergreens take carbon from the mycelium of fungus. Mycelium is the fungal mass of thready structures which decompose plant material in the forest. Since most of this decomposition occurs underground, we usually only notice the fungi's reproductive parts - the mushrooms. The wintergreens don't need above-ground leaves to photosynthesize if they steal enough nutrients underground from the hard-working fungi. There still seems to be some disagreement as to whether the white-veined wintergreens have evolved into different species - a leafy species (Pyrola picta) which is a partial myco-heterotroph and a leafless species (Pyrola aphylla) which is a full myco-heterotroph - or if they are just different forms or life stages of a single species. In any event, as with orchids, they have developed a special ecological relationship to survive in the dark forest.

Newly opened flowers of the Dudley's lousewort are white
while older and possibly pollinated flowers turn a soft lavender color.   

Last year, I was fortunate to find another small plant blooming in the forests of Portola Redwoods State Park - the Dudley's lousewort. I've been looking for this rare plant in redwood forests for years, but on that lucky day the world's expert on Dudley's lousewort explained why I had been looking in the wrong places. I'm waiting for it to bloom again this year so I can get better photos and share the unique ecological and historical factors that make this local plant so rare.

Fern-like leaves of the Dudley's lousewort.   

Although the Dudley's lousewort has green leaves, it also taps into roots of the forest trees to derive additional nutrients. Is there something about redwood forests that favor the development of such nutrient-robbing plants? The overbearing size and competitiveness of redwood trees, and their brothers the Douglas fir, may reduce the overall biological diversity of woody plants in the forest, but perhaps their ancient hugeness also creates unique ecological niches on the forest floor that encourage the development of small unusual plants. The chlorophyll-lacking orchids, broomrapes and coral roots come to mind and suddenly it seems like the quiet and open floor of the redwood forest is some type of botanical circus.

As I was researching this post, I noticed CalFlora showed an observation of white-veined wintergreen very near where I had been hiking. This observation was an isotype* collected in 1903 at Iverson's [cabin?] along Pescadero Creek which is now a historical site in Portola Redwoods State Park. With further research, I realized this early observation was made by A. D. E. Elmer who graduated from nearby Stanford University with a Masters degree in 1903 and soon afterwards went to the Philippines where he spent a lifetime collecting and describing over 1500 new plant species. I'm a little stunned to realize that 111 years later, I've shared a discovery with this famous botanist of a small but remarkable plant in the very same redwood forest. Someday, I'll have to visit the herbarium at the Santa Barbara Botanic Garden to figure out whether his specimen had leaves or was leafless.

It's these marvelous moments of small discoveries that make my life as an ecologist sparkle. That summer walk when I stumbled onto the wintergreen plant in Kentucky was also the teenage summer I read Sand County Almanac by Aldo Leopold at my parents' Minnesota cabin. That summer anchored my interest in botany and sealed my choice the next year of a college and a discipline of study which eventually led onto a career in ecology and today's meandering walks in redwood forests on the other side of the continent. Thank you little fairies of the forest.

I started this post whining about coast redwood trees as prime donne and I'm ending it by recognizing that these giants create small places for unique forms of life. If you are like me on hot summer days, you tire of waiting for condors to fly over a thistle-pulling site or of triple-checking under the barn door for basking rattlesnakes. Instead, let's go visit a redwood forest and look for small things. In the Santa Cruz Mountains, in addition to the oft-visited Big Basin Redwoods State Park, there's the quieter parks of Portola Redwoods State Park, Purisima Creek Redwoods Open Space Preserve, and many more. Don't forget to look down.

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*In simple terms, a holotype is a specimen collected by the person originally describing a newly identified plant and serves as a reference of its distinct characteristics. An isotype is a duplicate plant specimen collected at the same location and time as the holotype and serves as a backup reference. Both holotypes and isotypes are usually carefully preserved as pressed plants in herbariums where they are available for examination especially to determine if subsequently found similar plants are the same species or different.

Coast redwood, Sequoia sempervirens
Swordfern, Polystichum sp.
Manzanita, Arctostaphylos spp.
Huckleberry, Vaccinium spp.
White-veined wintergreen, Pyrola picta
Dudley's lousewort, Pedicularis dudleyi
Douglas fir, Pseudotsuga menziesii
Orchids, Piperia and Cephalanthera spp.
Broomrapes, Orobanche spp.
Coral roots, Corallorhiza spp.
Banana slug, Ariolimax columbianus
Turret spider, possibly Antrodiaetus riversi

Plants of the San Francisco Bay Region, Beidleman and Kozloff, University of California Press. Now available in a revised May 2014 edition. Excitedly waiting for my copy to arrive.

Robert Ornduff, Phyllis M. Faber, and Todd Keeler-Wolf, Introduction to California Plant Life, California Natural History Guides, University of California Press, Revised Edition 2003.

The Jepson Manual - Vascular Plants of California, University of California Press, 2012. Has anyone tried the interactive digital version of this 1568 page volume?

Aldo Leopold, A Sand County Almanac: and Sketches Here and There, 1949.

David Lukas, And This Little Spider Stayed Home, Bay Nature Magazine, July1, 2011.

CalFlora is a website with searchable information about the thousands of plants in California.
CalPhotos has over 400,000 searchable photos of plants, animals, and other natural history subjects.