Pando-The World’s Largest Organism

Within the Pando Clone
Fishlake National Forest, Utah
Courtesy & Copyright 2010 Ron Ryel
Utah State University

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

What we consider to be the world’s largest organism has changed over time. At one point, the largest animal crown went to a 150 ton female blue whale. And General Sherman, a 275 foot tall Giant Sequoia was the largest plant.

In 1992, scientists discovered a fungus in northern Michigan and proclaimed it to be the world’s largest organism. Not nearly as visually stunning as a Giant Sequoia, this type of fungus is a filagree of mushrooms and rootlike tentacles spawned by a single fertilized spore. Over time it had grown to cover 37 acres, most of this below ground. Subsequent mushroom hunts uncovered even larger specimens elsewhere.

Stretching over 1,600 miles and visible from space, I often hear the Great Barrier Reef called the world’s largest organism. But the reef is not a single organism. It is created from the limestone secretions of a great number of different reef-producing coral species.

Fungi, reefs and giant trees are all very worthy biological wonders, but the thing that gets my largest organism vote is right here in Utah. Like the Great Barrier Reef, it’s so vast you really need to see it from a plane or even satellite. Like General Sherman, it has its own name—Pando—-meaning “I spread” in Latin. Pando can be seen is spreading itself in Fishlake National Forest in south central Utah. So what is Pando? And why is it so remarkable?

Pando is a clonal aspen colony. Each “tree” that we see in an aspen forest is not an individual tree at all but a genetically identical stem connected underground to its parent clone. More trees arise from lateral roots, creating a group of genetically identical trees. But, biologically speaking, the colony is just one individual plant.

Recent genetic testing by Dr. Karen Mock of Utah State University confirms Pando’s enormous size- it covers over 106 acres and contains around 47,000 aboveground stems or suckers. When you consider the volume represented by the trees and root system, Pando easily wins the title of world’s largest organism. So far anyway.

Thanks to Dr. Karen Mock of Utah State University’s College of Natural Resources for her help in developing this piece.
For pictures and sources of the remarkable Pando, see www.wildaboututah.org

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Credits:
Photo: Courtesy & Copyright 2010 Ron Ryel, Utah State University
Text: Stokes Nature Center: Holly Strand

Sources & Additional Reading

WESTERN ASPEN ALLIANCE is a joint venture between Utah State University’s College of Natural Resources and the USDA Forest Service Rocky Mountain Research Station, whose purpose is to facilitate and coordinate research issues related to quaking aspen (Populus tremuloides) communities of the west. https://www.western-aspen-alliance.org/

American Cetatcean Society. Fact Sheet on the Blue Whale. https://www.acsonline.org [Accessed September 2, 2010]

DeWoody J, Rowe C, Hipkins VD, Mock KE (2008) Pando lives: molecular genetic evidence of a giant aspen clone in central Utah. Western North American Naturalist 68(4), pp. 493–497. https://digitalcommons.usu.edu/aspen_bib/3164
https://sci-hub.se/https://doi.org/10.3398/1527-0904-68.4.493

Grant, M., J.B. Mitton, AND Y.B. Linhart. 1992. Even larger organisms. Nature 360:216. https://www.nature.com/nature/journal/v360/n6401/abs/360216a0.html AND https://doi.org/10.1038/360216a0
https://sci-hub.se/https://doi.org/10.1038/360216a0

Grant, M. 1993. The trembling giant. Discover 14:83–88. Abstract:https://www.discovermagazine.com/the-trembling-giant-40013
https://digitalcommons.usu.edu/aspen_bib/2394/

Habeck, R. J. 1992. Sequoiadendron giganteum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://www.fs.fed.us/database/feis/ [Accessed September 2, 2010].
https://www.fs.usda.gov/database/feis/plants/tree/seqgig/all.html [Accessed Oct 12, 2025]

Mock, K.E., C . A. Rowe, M. B. Hooten, J. DeWoody and V. D. Hipkins. Clonal dynamics in western North American aspen (Populus tremuloides) Molecular Ecology (2008) 17, 4827–4844 https://digitalcommons.usu.edu/wild_facpub/163/
https://sci-hub.se/https://doi.org/10.1111/j.1365-294X.2008.03963.x

Volk, T. J. 2002. The Humongous Fungus–Ten Years Later. Inoculum 53(2): 4-8. https://msafungi.org/wp-content/uploads/Inoculum/53(2).pdf

The Associated Press, Study finds huge aspen grove continues to decline, The Salt Lake Tribune, Oct 22, 2018,
https://www.sltrib.com/news/2018/10/22/study-finds-huge-aspen/

Davis, Nicola, Sound artist eavesdrops on what is thought to be world’s heaviest organism, The Guardian, May 10, 2023, https://www.theguardian.com/environment/2023/may/10/sound-artist-eavesdrops-on-what-is-thought-to-be-worlds-heaviest-organism-pando-utah

The Sweet Song Of The Largest Tree On Earth, Science Friday, National Public Radio, May 12, 2023, https://www.sciencefriday.com/segments/listen-to-the-pando-largest-tree/

Dodders Not Daughters

Dodder in the Mojave Desert
Courtesy & Copyright Jim Cane

Do not mistake dodders for daughters. Parents appreciate a daughter’s hug, but no plant welcomes the embrace of dodder. Dodders are relatives of morning glories and bindweeds. Imagine the despised bindweed minus its leaves and green chlorophyll, just a snarl of twining vine looking like orange spaghetti, and you have a picture of dodder.

Dodders gave up chlorophyll for a parasitic habit. The stem of the seedling dodder actively circles about daily, seeking the scent of a host plant like some botanical bloodhound. It then grows toward its host plant, clambers aboard, and soon abandons its tiny roots altogether.

Bumps along the dodder’s orange stem become haustoria. These organs penetrate the host plant to tap into its phloem. The dodder vine grows prolifically with this pirated flow of sap, smothering the original host and spreading to others. Agriculturally, only the imported alfalfa dodder was a problem, but today we can mechanically separate dodder seeds from alfalfa seeds and so avoid inoculating fields with this parasite.

Dodder in the Mojave Desert
Courtesy & Copyright 2010 Jim Cane

Utah’s six native dodders attack a range of wild hosts, most commonly relatives of sunflowers. Other kinds of parasitic plants found in Utah include mistletoes, coral roots, broomrapes and the showy Indian paintbrushes. Other than the mistletoes, these are all root parasites. For some, the parasitic habit is merely optional, but for dodder, it is a way of life.

Dodder could be the basis of a botanical horror movie, but fortunately, infestations of dodder are uncommon and ephemeral in the wild, far more benign than some of the diseases and foreign weeds that disrupt our native plant communities.

This is Linda Kervin for Bridgerland Audubon Society.
Credits:

Dodder on Field Bindweed, Payson, UT
Courtesy & Copyright 2010 L. Bingham

Photos: Courtesy & Copyright Jim Cane
Courtesy & Copyright 2010 Lyle Bingham
Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

Pest Notes: Dodder, Pests in Gardens and Landscapes, University of California, UC ANR Publication 7496 https://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7496.html

Integrated pest management for alfalfa hay By University of California Integrated Pest Management Program, ANR Publications, 1981 – Technology & Engineering,
https://books.google.com/books?id=l7e5RvSPhkkC&pg=PA91&lpg=PA91&dq=dodder+#

Pests of landscape trees and shrubs: an integrated pest management guide ,Steve H. Dreistadt, Jack Kelly Clark, ANR Publications, 2004 – Gardening,
https://books.google.com/books?id=NEOLaUHPVdwC&pg=PA334&lpg=PA334&dq=dodder

Birds of a Feather Bird Collective Nouns

A “congregation”, a “stand”, or
(when flying) a “wedge” of ibises.
White-faced Ibis with
Marbled Godwits in background
Courtesy US FWS
Bear River Migratory Bird Refuge

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

The word flock is a collective noun that refers to a natural grouping of any kind of bird.

Certain bird species commonly flock together to feed, to travel or to help defend themselves. Flocks are usually thought of as composed of just one species but mixed species flocks also occur. A mixture of species can take advantage of a variety of abilities to find food or detect predators.

When you are talking about a group of single species–birds of a feather so to speak– there exist specific and sometimes eloquent terms that can be used instead of the word flock. We’ve all heard the term “gaggle of geese.” But did you know that earlier this spring, we saw a “season” of tanagers come through the valley? I have never seen a flock of owls, but if there were one, we could call it a “parliament” of owls. More common than a parliament of owls is a “congress” of crows. You can also call this same group a murder of crows.

A “pod”, “scoop”, or “squadron” of American Pelicans with Black-necked Stilts & White-faced Ibis Courtesy US FWS Bear River Migratory Bird Refuge

The word siege can apply to either bitterns or herons. A congregation may refer to plovers, egrets or ibises. A bouquet connotes warblers, hummingbirds or pheasants. However, for hummingbirds I prefer the collective terms shimmer or charm.”

Punsters might appreciate a seasoning of cinnamon teal, a chain of bobolinks a ladle of dippers or– my husband’s favorite—an outfield of flycatchers.

Sometimes, a bunch of birds in the water is different from a bunch of birds in the air. You’ll find a paddling of ducks in the water but a team of ducks flying overhead. Likewise a gaggle of geese is swimming, while a skein of geese is airbourne.

American Avocet Flock
Courtesy US FWS
Bear River Migratory Bird Refuge

One collective phrase is so evocative that it became the title of an entire book on collective nouns for birds and other animals. In An Exaltation of Larks, (now in it’s 3rd printing) author James Lipton explains that many collective nouns were hunting terms that originated in the 15th century or earlier. Nevertheless, the collective terms are correct and appropriate for use today.

This Saturday, August 21st, experience a shimmer of hummingbirds with Stokes Nature Center. Our hummingbird program will take place just east of the Second Dam in Logan Canyon. Drop in anytime between 8-11am. Signs or people will direct you on where to park. For more information call the Nature Center at 435.755.3239.

Cinnamon Teal Pair
In larger numbers a “seasoning of teal”
Courtesy US FWS
Bear River Migratory Bird Refuge

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Credits:
Photo: Courtesy Bear River Migratory Bird Refuge
Text: Stokes Nature Center: Holly Strand

Sources & Additional Reading

William Blades, Juliana Berners, Boke of St. Albans, Nabu Press (March 29, 2010) https://www.amazon.com/Boke-Saint-Albans-William-Blades/dp/1148085742

James Lipton, An Exaltation of Larks, Penguin Books, 1991, ISBN 0-670-30044-6. https://www.amazon.com/Exaltation-Larks-Ultimate-James-Lipton/dp/0140170960

Mixed-Species Flocking, Birds of Stanford Essays, Stanford University, https://www.stanford.edu/group/stanfordbirds/text/essays/Mixed-Species_Flocking.html

Animal Congregations, or What Do You Call a Group of…..?, Northern Prairie Wildlife Research Center USGS, https://www.npwrc.usgs.gov/about/faqs/animals/names.htm#birds

Names – Bird Groups and Young Birds, Utah County Birders, UtahBirds.org, https://www.utahbirds.org/featarts/2009/BirdGroupNames.htm

Virga: Teasing Rain

Virga: Teasing Rain

Virga courtesy and Copyright 2010 Kevin Connors a.k.a Virga teasing rain
Virga
Courtesy & Copyright 2010 Kevin Connors
August is the perfect month to observe virga in Utah, for it is the monsoon season here. Moist subtropical air is flowing northward from the Pacific Ocean and the Gulf of California. When this warm, moist air is driven upward by convection and mountains, towering thunder heads result.

Below the bellies of these dark clouds you sometimes see grayish windswept curtains or streamers that do not reach the ground. Meteorologists call them “virga”, virga spelled with an “i”, from the Latin for “streak”. The word “virga” is absent from the prose of Mark Twain and the exploratory reports of John Wesley Powell because the word “virga” was only coined 70 years ago.

Virga: Descending Precipitation & Downdrafts

Virga in Cache Valley courtesy and Copyright 2010 Jim Cane
Virga in Cache Valley
Courtesy & Copyright 2010 Jim Cane
These picturesque virga are descending precipitation. One might guess it to be rain, but most meteorologists agree that it is frozen precipitation which is melting and evaporating as it drops through our dry Utah air. Like a home swamp cooler, evaporation in virga causes cooling which leads to the chilly downdrafts that accompany our summer thunderstorms. In the humid tropics, rains can be lukewarm, but our summer cloudbursts are goose-bump cold, owing to the same evaporation which yields virga.

Virga are a tease for parched summer landscapes, a herald of wild fires ignited by dry lightning, and a generator of dust storms as downdrafts scour dusty salt flats. But mostly, the curtains of precipitation that are virga are a fleetingly beautiful element of our western summer skies, well worth a pause and a picture, especially if you are lucky enough to see one accompanied by a rainbow or a fiery sunset.

Virga in Tucson, AZ Courtesy and Copyright 2010 Julio Betancourt, Photographer
Virga in Tucson, AZ
Courtesy & Copyright 2010 Julio Betancourt
This is Linda Kervin for Bridgerland Audubon Society.
Credits:

Photos: Courtesy & Copyright 2010 Jim Cane
Courtesy & Copyright 2010 Julio Betancourt
Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

Jetstream, an online school for weather, NWS NOAA Southern Regional Headquarters, Ft worth, TX,
https://www.srh.noaa.gov/jetstream/index.htm

Virga in Tucson, AZ Courtesy and Copyright 2010 Julio Betancourt, Photographer
Virga in Tucson, AZ
Courtesy & Copyright 2010 Julio Betancourt

Fire weather : a guide for application of meteorological information to forest fire control operations, Mark J. Schroeder and Charles C. Buck, USDA Forest Service, https://training.nwcg.gov/pre-courses/S390/FireWeatherHandbook
/pms_425_Fire_Wx_ch_01.pdf

The Book of clouds, John A. Day, Sterling, 2005, https://www.amazon.com/Book-Clouds-John-Day/dp/1402728131

Live Worldwide Network for Lightning and Thunderstorms in Real Time, Blitzortung, https://en.blitzortung.org/live_lightning_maps.php?map=30