By Bruce Rottink, Volunteer Nature Guide & Retired Research Forester
At Tryon Creek State Natural Area (TCSNA), springtime is trillium (Trillium ovatum) time. Walking through the forest, who wouldn’t be delighted by these tough, brown, lumpy trilliums that look eerily like a piece of poop (“feces” for the delicate among you)? Surely something we can all….. What? Oh, I’m sorry! I forgot that you’re used to only seeing the parts of trillium that are above ground. Well then fasten your seatbelt pilgrim, ‘cuz today we’re taking a dive into the dark side. Thanks to an anonymous donor with hordes of trilliums in their private forest, we’re going to look at the part of the trillium that’s underground!
What’s Down There Anyway?
Pictured below is a whole trillium. The level of the soil is marked with the black dashed line. Above ground is the familiar white flower, the large green leaves (which are technically “bracts”), and the long stem (in botanical terms it’s actually a “scape”). As you can see, the two main things underground are the large, lumpy brown rhizome and the stringy white roots. When straightened out, the roots are about 30 cm (1 foot) long. I excavated this plant very slowly and carefully. The vast majority of the roots survived the extraction process, although there was some minor root breakage in the process. The orange ruler is 12 inches (about 30 cm) long.
The photo below gives a close-up view of only the subterranean elements of the trillium. The two principle parts are the profusion of whitish roots and the thick brown rhizome.
In the close-up photo below, the roots look pretty unremarkable. However, they do seem to branch less than many species I’ve observed. You might notice that the roots don’t originate evenly over the length of the rhizome, but rather are concentrated on the right-most end of the rhizome which bears the scape (stem) of the plant. This is the younger end of the rhizome. The left (older) end of the rhizome bears very few roots. Also notice the abrupt, rather than tapering, left end of the rhizome. It almost looks like the older (left) end of the rhizome has been cut off. In fact, as the rhizome ages, the oldest part of the rhizome is decayed away, leaving a flat end.
Cool, but how old is this trillium?
People have long been fascinated with the question of how old a particular trillium is. They have attempted to determine the age of a rhizome by counting leaf scars. The green arrows in the picture below are indicating just two of the “lumps” which are the leaf scars. The fact that the older end of the rhizome keeps decaying away is just the first of two major hurdles to correctly aging the plant.
A view down the rhizome from the young end of the rhizome gives a different, and perhaps more instructive view of the leaf scars. From this perspective each of the leaf scars is a little shelf, with the leaf coming out of the flat top side of the shelf. The top of each shelf appears to be full of some “knobby” structures, which I have cheerfully assumed are the healed-over stubs of the vascular tissue (like veins) that connected the leaf to the rhizome. The green arrows point to individual shelf-like leaf scars.
It has been widely assumed that by counting the leaf scars you could determine the age of the plant, much as you might count tree rings. If the trillium produced only a single stem (scape) per year, this would be a wonderful system. Sadly, it is not so simple. This is the second major hurdle to aging a trillium plant by counting leaf scars. Namely, that the trillium can produce more than one stem per year, and thus more than one leaf scar per year. The example used above produced one leaf this year. However, another trillium, which I had growing in a pot in my backyard, is pictured below. Clearly it has produced two stems (scapes) this year, and thus will leave two scars in the future. As a side note, you can see that both of these stems blossomed.
The rhizome of the trillium I dug out of the forest has, as near as I could determine, 45 leaf scars. Assuming that each year it produced either one or two leaf scars, it is somewhere between 22 and 45 years old. But that’s just the part of the rhizome that hasn’t rotted away yet. So much for being able to determine the age of trilliums!
So what does the rhizome do?
One of the rhizome’s main functions is as the food storage organ for the plant. The huge amount of energy stored in this rhizome over winter is the reason trilliums shoot up so quickly in the spring. The trilliums don’t have to manufacture food as they burst up from the ground. Instead they draw upon the massive food reserves already in the rhizome. Below is a longitudinal (“lengthwise”) cut through the rhizome. This rhizome is approximately 1 inch (2.5 cm) in diameter. The inside has approximately the feel and texture of a potato. Of course after the spring burst of growth, the green parts of the trillium above ground take on the task of replenishing the food reserves for next year’s scape, bracts and flowers.
The trilliums of TCSNA are probably a lot older than we first imagined. They are not only the Princesses of the Forest, they are tough, long-lived members of our forest community.
Native American Uses of the Forest
By Bruce Rottink, Volunteer Nature Guide and Retired Research Forester
For thousands of years before settlers from the eastern United States or Europe arrived in the vicinity of what is now Tryon Creek State Natural Area (TCSNA), Native Americans called this forest home. The Native Americans used resources ranging from rocks to trees to animals. However, the basis for much of the Native American life was the plant life of this area. They relied on the forest and waterways for everything; food, medicine, tools, clothes, everything!
What kinds of plants did they eat?
There were lots of plants and fruits the Native Americans ate. Some of the more tasty items were the berries from the forest, like the salal (Gaultheria shallon) berries. Pictured below are the plant and berries. I’ve planted salal in my front yard, and they are delicious on my morning cereal!
Another food the Native Americans sometimes ate were the berries of the Oregon grape (Mahonia nervosa). In the photo below, the blue-colored berries are almost ready to eat, while the greenish ones have a way to go before they are ripe.
I’ve tasted Oregon grape berries too. My taste buds’ response was, o-o-o-o-kay! I think they’re about half way between yummy and yucky. According to ethnobotanists, people who study how different groups of people use plants, the Native Americans would sometimes mash the fruits of the salal and Oregon grape together. In this way, they had a greater total quantity of food, which still tasted “kind of” good.
Another category of food plants is represented by the skunk cabbage (Lysichitum americanus) pictured below. This plant has a large underground tuber (note: potatoes are also tubers). Unfortunately, the skunk cabbage tuber tastes awful. It had to be specially prepared to become even edible. Ethnobotanists refer to this as a “starvation food” meaning that you only ate it when the alternative was starvation. If you’ve ever smelled a skunk cabbage in the spring, you understand why it wouldn’t necessarily pop into your mind as a good food item!
What kind of medicine is in the forest?
For the Native Americans, the forest was their drugstore. Just one of the many medicinal plants used by some Native Americans was the licorice fern (Polypodium glycyrrhiza). The pictures below show the licorice fern growing on the side of a tree at TCSNA and the second photo shows a cleaned-up licorice fern plant that was growing on a branch that was blown down during a windstorm. The rhizome can be thought of as a perennial stem, while the leaves come and go with the seasons.
The Native Americans cleaned up the rhizome of the licorice fern and chewed it as a cough and sore throat remedy. Once when I was not at TCSNA, I cleaned up a licorice fern rhizome and chewed it a bit. It does taste faintly like licorice. Within 30 seconds of starting to chew the rhizome, I got a tingle right in the back of my throat. Although I was perfectly healthy at the time, the fern was definitely affecting me. It would have been interesting to see the effect if I’d had a cold or sore throat.
What kind of tools did they find in the forest?
One of the tools the Native Americans found in the forest was the horsetail (Equisetum spp.), pictured below. This primitive plant contains a lot of silica crystals. Silica is the most common material found in sand. The Native Americans used this as a “natural sandpaper” for finishing their wooden tools. The effectiveness of this tool can be demonstrated by using it to polish a penny.
The effectiveness of polishing is shown in the “before and after” photos below.
What kind of clothes did they make from forest plants?
The western redcedar tree (Thuja plicata) had many uses. To give just one example, its bark is very fibrous. With careful harvesting and care it can be used to produce everything from rope to clothes. Pictured below is a cedar bark rain hat. These were widely made and used by the Native Americans on the Pacific coast. According to some sources, they would sometimes treat this hat with pitch to make it even more water repellent.
But of all the clothing that the Native Americans made from forest plants, the one that always intrigued me was that they used moss for baby diapers. I wondered how well those would work. Strictly as a public service, I decided to run an experiment and find out.
You personally tested moss as diapers? Seriously?
Before your imagination runs wild (it may already be too late), let me explain. I took samples of five water-absorbing things:
- A major brand of modern disposable diaper
- A sponge
- A pile of moss
- A traditional cloth diaper
- A bunch of paper towels
I weighed each item dry, making sure I had between 60 grams and 90 grams of each material (this is about 2 to 3 ounces). I then soaked each item (separately) in water completely covering the test material with water for 15 minutes. Then I put each material on a sheet of screen to drain. When the drops of water falling out of the material were 10 or more seconds apart, I considered the material to be completely drained. I then weighed each item wet. I calculated “absorbency” by dividing the weight of water absorbed by the dry weight of the material.
The results are displayed in the chart below.
Modern diapers with their SAP (Super Absorbent Polymer) ingredient can absorb more than 80 times their weight in liquid! But let’s cut to the chase. I was fascinated to see that moss, the key ingredient in the Native American diaper could absorb 7.4 times its dry weight in water. In contrast, a classic 100% cotton, all-cloth diaper can only absorb 3.5 times its own dry weight in water. So the Native Americans were using the superior diapering material! Wow!
At home in the forest!
To the Native Americans, the forest was their home, their grocery store, their pharmacy, their hardware store, their everything! They adapted to their environment to meet all their needs.
The Plants Fight Back!
By Bruce Rottink, Volunteer Nature Guide and Retired Research Forester
Plants may seem like passive members of the Tryon Creek State Natural Area (TCSNA) forest community. They stand in one place for many years, stoically enduring every insult the ecosystem throws at them. Their reactions are neither flashy like birds, nor noisy like squirrels. Their efforts at survival are more subtle, yet often very effective.
Plants are subject to a wide range of diseases, primarily caused by fungi or bacteria. Unlike many animals, plants don’t have an immune system to fight off infections. Still, over many generations, plants have developed some defensive tricks that might not be obvious to humans.
Okay, how do plants cope with infections?
One method of dealing with disease is to just give up and start over again! For example, by early August of 2013, all the leaves of one particular vine maple (Acer circinatum) near Obie’s Bridge were heavily infected and damaged by a microorganism. The photo below shows the extent of damage to typical leaves.
Damaged as the leaves were, the plant reacted by dropping all of the diseased leaves in early August, and growing a new set of uninfected leaves. The uninfected leaves served it well through the remainder of the growing season. The new leaves are shown in the photo below. You’ll note in the photo that the leaves on the lower portion of this branch have not yet grown out, and may not grow out this year.
Wow, that seems like overkill!
Yes, this is a radical approach to dealing with leaf diseases, but when all other defenses fail, the plant has little choice. More often, plants deal with leaf infections by a process known as “compartmentalization.” This is illustrated in the photo of the Oregon grape (Mahonia sp.) leaf below. This leaf has been attacked by a fungus. The fungal attack has killed the leaf tissue, as indicated by the pale circular (and now fractured) area of leaf tissue. In response to the infection, the leaf has created a barrier, seen as a thin black line, to stop the infection from spreading. The black spots within this area are places where the fungus has produced spores.
Actually, the leaf has responded to the fungal attack in two ways. First, it has created a physical/chemical barrier to the fungus, which is the black ring surrounding the infected spot. This will stop the fungus from spreading any further into the leaf. Secondly, the reddish areas of the leaf are colored by the natural chemical called anthocyanin. Scientists have discovered two very cool things about anthocyanin. First, scientists have shown that anthocyanin interferes with the growth of fungus. Second, scientists have discovered that many plants start producing anthocyanin when they sense a fungal infection. So the production of anthocyanin is the plant’s form of chemical warfare, triggered by the presence of fungus.
In the interests of full disclosure, the anthocyanin may “appear” for one of two reasons. First, it may have been there all along, and only becomes visible when the normal green pigment (chlorophyll) disappears. Or secondly, it may have been synthesized by the plant in response to the attack. While it is not definitive proof, the photo below of a leaf attacked by fungus shows the (red) anthocyanin only near the region of fungal attack. This in spite of the fact that the chlorophyll has disappeared from the leaf. This suggests to me that the leaf was not filled with anthocyanin that was revealed when the chlorophyll disappeared, but rather the anthocyanin was specifically synthesized in response to the fungal attack.
What happens when decay gets into a tree’s trunk?
When a tree is dealing with a fungal attack on its main stem, or trunk, just giving up is NOT an option. Once wood has started to decay, it doesn’t “heal.” And plants, as far as we know, don’t have immune systems. So instead, the tree uses the same compartmentalization technique as it uses with leaves. It isolates the fungus to make sure it doesn’t spread throughout the entire tree trunk.
Below is a picture of the cross section of an alder (Alnus rubra) tree that was growing near the Tryon Creek Nature Center. It was cut down because it was a hazard to folks using the park. The picture clearly shows the solid reddish-brown wood, the gray-ish area of rotten wood probably caused by a fungus, and the thin black barrier the tree has developed to compartmentalize the infection.
Park Ranger Dan Quigley found another very interesting rotten tree while cleaning up some “tree messes” around TCSNA. He cut me a “tree cookie” (a cross-sectional slice of the main trunk) and hauled it back to the shop. THANKS, DAN! This specimen of bigleaf maple (Acer macrophyllum) is interesting in that this tree appears to have been attacked by rot twice. It probably was wounded and infected once, and then sometime later, it was wounded and infected again. In older trees this is not uncommon. Again the black lines are the barriers created by the tree. (For size purposes, note that the tree cookie is overlapping both edges of the 29” wide picnic table it is resting on).
The wood at the very center of the tree, inside the first barrier, was so rotten that it has disappeared (probably in the cutting/handling process, if not prior to that). Most of the barrier was destroyed too. However, one small section of the first barrier is still present.
This specimen provides a rare opportunity to view the “barrier” up close. I scraped away some of the rotten wood inside of the 1st attack barrier. The photo below shows a side view of the barrier, with the barrier being a darker color than the rest of the wood.
I carefully dug out some of the rotten wood between the first barrier strip and the bark. Then I took the photo below looking pretty much straight down the tree trunk. In this photo, you can see that the barrier strip is a real physical entity. It is approximately the thickness of, and as strong as, the material in a standard manila file folder.
Plants are tough!
Plants are rich storehouses of the energy that fungus and other disease-causing organisms need for their own success. Plants are under constant attack. While their defense mechanisms generally allow the whole plant to survive, it is often at the cost of sacrificing a part of themselves to the disease. Somehow, both the plants and the fungus have survived for millions of years, making our forest the home to some of the toughest organisms that you can imagine.
* Thanks to Jay W. Pscheidt, Extension Plant Pathology Specialist and Professor of Botany and Plant Pathology at Oregon State University for his input on this post. He both confirmed some things I thought I knew, and provided some new information on this topic! This exemplifies one of my favorite quotes, “None of us is as smart as all of us!” That said, I take full responsibility for any errors in this note! — Bruce Rottink