Posts Tagged ‘Fungus’

I Like Lichen

May 6, 2015

Lichen-12

Lichens are a strange and wonderful life form. They are composite organisms made up from as many as three biological kingdoms; fungus, algae and bacteria. While they all need each other in this symbiotic triangle of life, the dominant partner is a fungus.

Lichens are fungi that have discovered agriculture- lichenologist Trevor Goward

The fungus benefits from this relationship because algae and cyanobacteria produce food by photosynthesis. The algae or cyanobacteria benefit by being protected from the environment by the filaments of the fungus, which also gather moisture and nutrients from the environment, and usually provide stability. This little arrangement works very well as lichens can be found in almost every habitat and geographic area on the planet. It is estimated that 6% of Earth’s land surface is covered by lichen. They are also considered the world’s oldest living organisms. Cooperation is a powerful survival tool and it accomplishes what evolution alone cannot provide in a single creature.

Lichens grow where other things can’t such as desert sand and bare rock. Their trick is to hibernate or shut down metabolically during extremes of heat, cold or drought. When they get wet conditions they reawake to capture solar energy and let their true colors shine. This is because moisture causes the lichen’s surface skin to become more transparent, exposing the colorful photosensitive partner (the photobiont) to light. This transition can happen within minutes. The next time you see some dried-up lichen, sprinkle it with water and watch it wake up.

It has been a soggy week here in Boulder, the cloudy wet conditions are getting to me and I need some color. This is perfect weather for our tiny lichens to come out of hibernation and make the rocks glow with color. Finding them is easy, just seek a place with rocks. Maybe the name appealed to my wishful thinking but I decided to head up Sunshine Canyon (40° 2’1.35″N, 105°18’56.63″W) to see what’s on the rocks. As you can see, the lichen was full of color on this grey and rainy day…

The Rocks Were Alive

The Rocks Were Alive and Photosynthesizing in Sunshine Canyon. Green Algae in the Forest.

This called for my close-up lens (60mm macro). Now everything is revealed in this miniature world…

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Lichen Abstract Art

The moss was pretty well soaked too…

Moss Droplets

I interrupted this Abert’s Squirrel’s lunch (this photo was taken with a 200mm zoom)…

Aberts Squirrel

Thanks to lichen It turned out to be a Colorful Colorado day despite the soggy weather.

Improbable Parasites On the Mesa Trail

June 6, 2013

“Less than the coral-root you know
That is content with the daylight low,
And has no leaves at all of its own;
Whose spotted flowers hang meanly down.”

-On Going Unnoticed by Robert Frost

While enjoying our showy spring wildflower display on the North Mesa Trail I came upon a small brown plant shyly hiding on the forest floor pine duff (partly decayed organic matter). While this Spotted Coralroot (Corallorhiza maculata) does not need to be in the spotlight its very existence is an improbable tale.

Coral Root Orchid Plant (Corallorhiza maculata)

Coralroot Orchid Plant (Corallorhiza maculata) “Corallorhiza” is Greek for “coral root” and “maculata” is Latin for “spotted”

On closer inspection you can see the tiny Orchid blossoms; this is one of our tiny native Colorado Orchids

Coral Root Orchid Plant Flowers

Coral Root Orchid Plant Flowers

I was surprised when I discovered my first Colorado Orchid; I thought they only grew in lush, tropical environments. Actually there are more than 25,000 species of Orchids. There are more orchids than any other kind of flowering plant except those in the aster and daisy families. Although they are most common in the tropics, Orchids can be found almost everywhere except Antarctica and the very High Arctic, occupying almost any habitat, including on other plants (epiphyte). One, known as a Western Underground Orchid, lives entirely underground. There are at least 33 types of native Orchids in Colorado (compared to only four Native Hawaiian Orchids).

Early Coralroot

Early Coralroot

Coralroot Clump

Coralroot Clump

Orchid seeds are too small to contain stored nutrients. To solve that problem they must be infected by a specialized fungus that establishes a symbiotic relationship, sharing food and enzymes until the young plant can survive on its own. While many plants use soil fungi as a startup strategy, some orchids have taken an evolutionary sidestep and do not use photosynthesis at all. Orchids were formerly considered to be capable of directly living off of dead organic material (saprophytic) in lieu of photosynthesis. Recent studies have revealed that plants cannot live off of dead organic material; only fungi can do that. It is now known that plants previously described as saprophytes are actually parasites living off of fungi. These fungi transfer nutrients from the host plant to the parasite (called Myco-heterotrophy). The fungi themselves are parasitic on the roots of living plants.

Our Coralroots are the type of Orchid that never becomes self-sufficient. Researchers have discovered that members of the genus Corallorhiza are parasitic Orchids. They derive all of their nutrients from mycorrhizal soil fungi in the family Russulaceae (think mushrooms). Despite their name they have no roots but only hard, branched rhizomes. The relationship with the soil fungus begins before the microscopic seed can germinate and continues for the life of the plant. Finding the right fungi to cheat for life is a chancy business and most seeds just die. To improve its survival rate the plant produces millions of seeds per flower. This is why the seeds must be small and light (the Coralroot seed is only about 0.2 mm in diameter). Those few that do go on to survive parasitize their fungi into forming a coral-like formation enveloping the root that resembles a clump of soft corals. Our pretty little Orchid is a lifelong biological cheater, cheating its fungus cheater…

Coralroot Root Fungus Host

Coralroot Root Fungus Host

In addition to the unlikely success of its seed, the complex mechanisms which orchids have evolved to achieve cross-pollination are risky as well. These mechanisms were investigated by Charles Darwin and described in his 1862 book Fertilisation of Orchids. The book was his first detailed demonstration of the power of natural selection, and explained how complex ecological relationships resulted in the coevolution of orchids and insects. The view has been expressed that the book led directly or indirectly to all modern work on coevolution and the evolution of extreme specialization.

Orchids have developed extremely specialized pollination systems often relying on a specific insect for success. The chances of being pollinated are often rare, so orchid flowers usually remain receptive for very long periods and most Orchids deliver their pollen in a single mass. When a protective cap is dislodged by a specific pollinator the pollen baring part called the anther is exposed to the insect’s body. Two pollen masses (called pollinia) are attached to a sticky pad (viscid) which readily adheres to the bodies of insects. When insects visit another orchid blossom, the pollinia are transferred to a sticky surface. Each time pollination succeeds, thousands of seeds can be fertilized.

Coral Root Orchid Flower

Coral Root Orchid Flower Showing Petals, Sepals, Lip, Column and Anther Cap

I observed many hikers walking by this extraordinary example of evolutionary complexity without even noticing its unlikely existence…

Mandy Can't Find the Coralroot, Can You?

Mandy Can’t Find the Coralroot, Can You?

nor its diminutive beauty…

A Small Improbable Event

A Small Improbable Event

The Canadians apparently appreciate the Corallorhiza striata (Striped Coral Root Orchid)…

Striped Coralroot 2006 Canadian Stamp

Striped Coralroot 2006 Canadian Stamp


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