(Continued from Part 1)
A tiny fragment of the Trembling Giant in the fall is pictured below.
Appendix: Rhizomes (with Emphasis on Vegetative Reproduction)
It was mentioned above that the spice ginger is derived from the rhizome of the ginger plant. We have not previously encountered rhizomes in this series of e-mails, so this appendix covers them. Since discussion of vegetative reproduction in these e-mails has mainly been limited to grafting (1 Feb and 27 Mar 2015), the role of rhizomes in vegetative reproduction will be stressed here. (Vegetative reproduction is to be contrasted with sexual reproduction. In sexual reproduction in plants, the genes from the parents are mixed to form a new set of genes, and these genes are incorporated into a seed, which then sprouts to reproduce. In vegetative reproduction, the plant reproduces just by growing; since there is no mixing of genes, the product is a clone, unless a mutation happens to occur.)
A rhizome, though it is underground, is not a root since it does not perform the root functions of taking in water and nutrients. In fact, a rhizome is a shoot just like the parts of the plant that we see growing above ground. Most shoots exhibit what is called a geotropism, which means that they grow opposite to the direction of the force of gravity, i.e., they grow up. Rhizomes, in contrast, exhibit what is called a diageotropism, which means that they grow perpendicular to the force of gravity, i.e., they grow horizontally.
Rhizomes serve two main functions. First, they are storage organs that hold protein and starch that can be used whenever the plant needs them. Second, the rhizome can send up new vertical shoots, which allow the plant to reproduce, and it can also send out new roots, which feed the plant. If a rhizome is divided into two pieces, each piece can start a new plant. Examples of plants in addition to ginger that spread by rhizomes are bamboo, Venus flytrap, poplars, irises, hops, and asparagus.
For a concrete example of reproduction by rhizomes, consider the quaking aspen. The rhizome spreads under the earth, and every once in a while sends up a new trunk. This process of vegetative reproduction by rhizome is described by an article in Bioscience, quoted in Wikipedia:
...quaking aspen regularly reproduces via a process called suckering. An individual stem can send out lateral roots [sic] that, under the right conditions, send up other erect stems; from all above-ground appearances the new stems look just like individual trees. The process is repeated until a whole stand, of what appear to be individual trees, forms. This collection of multiple stems, called ramets, all form one, single, genetic individual, usually termed a clone [genet].
Therefore, you might be looking at a grove of quaking aspens and thinking that you are looking at a number of separate trees. In fact, this is one organism that is comprised of the many trunks, plus the shared rhizome. Here is some useful terminology: The genet is the entire organism, and a ramet is each individual trunk. This terminology applies not just to quaking aspens but to any plant that spreads with a rhizome. (Some think that the quaking aspen got its name since the tree quakes in fear because the cross on which Jesus was crucified was made of aspen.)
The most famous rhizome on earth belongs to a quaking aspen genet called the Trembling Giant (or Pando). It is located in Fishlake National Forest in the Wasatch Mountains in Utah, which is marked by a red dagger in the map below. The Trembling Giant covers 106 acres, has about 47,000 ramets, i.e., trunks, and weighs about 13 million pounds. Estimates of its age range from 80,000 to a million years old. (An individual trunk is rarely more than 200 years old; the Trembling Giant is so old because it keeps growing new trunks as old ones die.) The Trembling Giant was discovered in 1968, and the claim that it was a single organism was initially based on morphology, e.g., the angle between the trunk and branches, and the fall colors, both of which are genetically determined; since then, DNA testing has confirmed this claim. Quaking aspens are dioecious, i.e., have male and female flowers on different trees; the Trembling Giant is male.
The advantage of having a large and dispersed rhizome is explained by Michael C. Grant:
Since the quaking aspen is a pioneer tree that typically invades treeless land and is then replaced by other trees in the floral succession, you will wonder how the Trembling Giant could last so long. Wikipedia explains:Aspen stands are just as complex below ground as above. Their intricate network of roots can ferry nutrients from one part of the clone to another. Roots near an abundant water supply, for example, may provide water to other roots and shoots in a much drier area. These parts of the clone can return the favor if their roots have access to crucial nutrients missing from the wet area. By distributing its water and nutrients over its entire expanse, a quaking aspen clone can survive in a patchy environment where other trees might die off.
Pando is thought to have grown for much of its lifetime under ideal circumstances: frequent forest fires have prevented its main competitor, conifers, from colonizing the area, and a climate shift from wet and humid to semi-arid has obstructed seedling establishment and the accompanying rivalry from younger aspens. During intense fires, the organism survived underground, with its root system sending up new stems in the aftermath of each wildfire. [Link omitted]
Ramets send a hormonal signal to the rhizome that suppresses the formation of new ramets; when there is a fire, however, and numerous ramets are destroyed, the resulting lack of this hormone means that the rhizome responds by sending up numerous new ramets to populate the ravaged area.
If there were were no humans, the Trembling Giant would eventually die not because of some internal clock but because of climate change or because it succumbed to a disease. With the coming of humans, however, new dangers arise. In the area where the Trembling Giant lives, not only have homes been built but also campgrounds with roads, picnic tables, and toilets. Also, the presence of people has led the Forest Service to suppress wildfires, which are the breath of life to the Trembling Giant. Without fire, conifers will gradually encroach on its edges and shade it out, then, since the the quaking aspen cannot tolerate shade, the Trembling Giant will die. Not even the oldest and largest organism on earth can withstand the pestiferous humans. No wonder the Giant trembles.
In 2006, the United States Postal Service issued a sheet of stamps, "Wonders of America: Land of Superlatives," One stamp labeled "Largest Plant:Quaking Aspen" illustrates the Trembling Giant.
That's all I have to say about rhizomes. Perhaps some future e-mail will cover other plant organs used for reproduction or storage such as stolons, corms, and tubers.
Party Tip
The sheet of stamps mentioned above that features the Trembling Giant, "Wonders of America: Land of Superlatives" (see picture below), also depicts another 39 superlatives. Your party tip is to start a discussion in which your guests recount their experiences of the superlatives they have encountered. Purchase this sheet at this site and give it to the guest who has experienced the most superlatives. You will find that these stamps will release a flood of nostalgia that will send your guests home with the sense of a life well lived. Here are some of my favorites.
- "Oldest Trees: Bristlecone Pines," which Mike and I inspected at Cedar Breaks National Monument in June of 1984 not far from Cedar City, Utah, which, as you can see in the map above, is down the interstate to the south of Fishlake National Forest. These trees, thousands of years old, were stunted and contorted, looking more dead than alive. They lived at altitude on the edge of a cliff with a 2000 foot drop and were subject to a never-ceasing, strong, cold wind. Below is a picture of Cedar Breaks and another of some of the healthier bristlecone pines at Cedar Breaks; a third picture shows more typical, decrepit bristlecone pines (location unknown). I lost the bristlecone pine cone that I smuggled home as a souvenir.
- "Windiest Place: Mount Washington," which Mike and I climbed in June of 1982 and again in June of 1983. At the top of Mount Washington, we did not experience the 231 mph wind reported in 12 April 1934, which is the highest wind ever observed not associated with a tornado or hurricane.
- "Tallest Cactus: Saguaro," which my sister and I inspected in Nov 1977 at Giant Saguaro National Monument outside of Tuscon, AZ. Below is a picture of me paying homage to the giant saguaro. Giant saguaros in art works are almost always depicted in the ideal configuration with two arms on opposite sides of the plant at unequal heights; you can survey hundreds of actual giant saguaros and not find a single one that adheres to this ideal.
Travel Tip
You will want to visit the Trembling Giant and immerse yourself in the awe that comes from being in the presence of what can lay claim to being both the largest and the oldest living organism on earth. As the map above shows, you can fly to Salt Lake City and then take I-15 south to Fishlake National Forest. You can drop by Fish Lake, the largest Mountain lake in Utah, which features trophy fishing, or you can watch for mountain goats. If, however, you want to skip these attractions, use your GPS to go straight to the coordinates of the Trembling Giant, N38.525, W111.75. Be aware that the Trembling Giant is at an altitude of 8848 feet, so be prepared to deal with altitude sickness. Google Maps shows numerous photos of the area. Most of these photos show what appear to be quaking aspens; perhaps they are ramets of the Trembling Giant. Here are two of these pictures.
- Fish Lake in fall colors.
- Doctor Creek Campground. You will need accommodations, and this campground might please you. My conjecture is that all those white trunks with dark splotches are quaking aspens. This might be one of the campgrounds mentioned above that is built on top of the Trembling Giant.
You might want to hack off a piece of the Trembling Giant's rhizome, bring it back East, and plant it. Perhaps you could establish an eastern outpost of the Trembling Giant. This would make it easier for those of us in the East to worship this majestic organism. Perhaps the two branches of the Trembling Giant will eventually meet, and you can hold the analog of the golden spike ceremony that marked the completion of the transcontinental railroad. In fact, for this ceremony you might want to employ the original golden spike (pictured below), which is now displayed at the Cantor Arts Museum at Stanford University. To bring out the full resonance of this event, you will want to mimic the original celebration held on 10 May 1869, which is pictured below in the famous photograph by A.J. Russell. (You might have seen later copies of this picture in which the alcoholic beverages at the focal point were airbrushed out.)
If you fall in love with Fishlake National Forest and decide you want to work there, here is how you apply for a job.
I have gone through the Fish Lake National Forest website and, strange to say, there is no mention of the Trembling Giant. I guess they don't want to encourage thrillseekers.
While in the area, you might want to cruise down the interstate, drop by the Cedar Breaks National Monument, and view the bristlecone pines.
References
Bown, Stephen R., Merchant Kings: When Companies Ruled the World, 1600-1900, Thomas Dunne Books, 2009. For a description of this book, see the e-mail of 9 Oct 2015.
Fernald, Merritt Lyndon and Alfred Charles Kinsey, Edible Wild Plants of Eastern North America, Gray Herbarium of Harvard University, Special Publication, Idlewild Press, 1943. For a description of this book, see the e-mail of 16 May 2015.
Grant, Michael C., "The Trembling Giant," Discover, October 1993, no pagination in the on-line version. This article is written by a scientist who has studied the Trembling Giant and who bestowed its alternate name, Pando ("I spread" in Latin). This article is available at http://discovermagazine.com/1993/oct/thetremblinggian285. This article, supplemented by Wikipedia, gives a good, quick, popular introduction to the Trembling Giant. Since there are no page numbers in the Internet version, which is all I have access to, above I have referred to this article with a link. I first heard about the Trembling Giant in 1982, but I did not again encounter it until I came to write this e-mail. Such are the pleasures of fruit exploring.
Keay, John, The Spice Route A History, University of California Press, 2006. For a description of this book, see the e-mail of 9 Oct 2015.
Krondl, Michael, The Taste of Conquest: The Rise and Fall of the Three Great Cities of Spice, Ballantine Books, 2007. For a description of this book, see the e-mail of 9 Oct 2015.
Niering, William A., The Audubon Society Guide to North American Wildflowers: Eastern Region, Alfred A. Knopf, 1979. For a description of this book, see the e-mail of 12 Jun 2015.
Turner, Jack, Spice: The History of a Temptation, Vintage Books, paperback, 2005 (first published in hardback in 2004). For a description of this book, see the e-mail of 9 Oct 2015.
Valenzuela, Hector, Farm and Forestry Production and Marketing Profile for Ginger (Zingiber officinale), in C.R. Elevitch, Speciality Crops for Pacific Island Agroforestry, Permanent Agricultural Resources, Holualoa, Hawaii, http://agroforestry.net/scps, 2011. I only had access to the on-line version at http://agroforestry.net/images/pdfs/Ginger_specialty_crop.pdf.
