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Posts Tagged ‘Eastern Speckled Shield Lichen’

When the snow is piled high and it seems like anything of any interest is buried under it I go to the woods and look at the trees. They’re never buried and they always have something fascinating to show me, like lichens. Lichens will grow on just about anything including glass, but this post is devoted to those I’ve found on trees.

The yellow on the trunk of the tree in the previous photo I believe is made up of fringed candle flame lichens (Candelaria fibrosa) like that seen above, but I’m not a lichenologist and I don’t own a test kit or microscope, so don’t hold me to it. This lichen must like a lot of water because I see it a lot on the lower parts of trees that grow near irrigation systems, with trunks that are almost always wet in warmer months. This lichen always reminds me of scrambled eggs.

What prompted me to do this post was a visit to the doctor’s office. I walked past a tree that had bushy green things all over it and luckily I had my camera with me, so I ran back and took a few quick shots before the appointment. This is the first time I’ve seen anything like this.

It has taken quite a while to figure out what this lichen might be called but its green body (thallus) with flattened strap like branches and white fruiting bodies (apothecia) have led me to finally settle on the tufted ramalina lichen (Ramalina fastigiata.) A lichen guide from 1902 says this lichen is “very common in New England” but I’ve never seen it. It is also apparently very common in the U.K.

This is an odd lichen with large apothecia that look like they just erupt anywhere on the body but also look like they are stalked, depending how you look at them. Some are convex and some concave and some have rims and some don’t. The white apothecia are reproductive structures where the lichen’s spores are produced. This is a very interesting lichen that I hope to see more of without having to visit the doctor.

The doctor’s trees were full of surprises. I almost made myself late taking photos of the tufted ramalina so I went back later and looked the trees over a little more closely. When I did I found another lichen I had never seen; the Eastern speckled shield lichen. According to what I’ve read it grows on the bark of deciduous trees, has a bluish gray body with large brown apothecia, and has brown to black dots (pycnidia) on the surface of the body. This lichen has all of that but what it doesn’t have that I could see are white, grainy bits called psuedocyphellae so I can’t be 100% sure of my identification. If you know more about this or any of the lichens seen here I’d love to hear from you.

Common greenshield lichen (Flavoparmelia caperata) is indeed very common. It’s a large lichen and colonies of them often grow to cover entire trees. Older ones wrinkle like the example seen here. Like many lichens they change color, and go from grayish when dry to yellow green when wet. This example had just been rained on a day or two before I took the photo but was still dry, so it doesn’t take them long to dry out. This lichen also taught me that many lichens prefer growing on the shady side of trees, presumably so the sun doesn’t dry them out quite so fast.

If you saw what looked like blue eyes near the greenshield lichen in the previous photo they were just the apothecia of the star rosette lichen (Physcia stellaris) seen here. The apothecia of this lichen are actually dark brown but they have a powdery wax coating that can cause their color to change depending on the light. Plant parts with this powdery waxy coating are said to be pruinose and a good example of it is the “bloom” on blueberries, grapes, plums, and other fruit. The coating reflects light and protects what it coats from the sun. Depending on the angle of the light these apothecia can appear blue, gray, brown or black. That’s why it pays to visit lichens several times.

I was shocked to find a tree with hammered shield lichens (Parmelia sulcata) all over it, because my experience up to this point has shown it to be on the rare side here. There didn’t seem to be anything special about the deciduous tree they were on, but it was in a sheltered spot. Hammered shield lichen is said to have a large variety of named varieties and forms, so it can be tough to pin down.

Hammered shield lichens are silvery gray and their many sharp ridges and depressions makes them look like they’ve been hammered out of a piece of steel. Fruiting bodies are said to be rare and I’ve never seen them. It is said to have powdery, whitish soredia but I’ve never seen them either. This one had granular bits that looked like soredia on its lobe edges but they were gray, so maybe it’s one of the aforementioned varieties.

Poplar sunburst (Xanthomendoza hasseana) is a very pretty lichen but it isn’t very common, in my experience. It’s a good one to study because it has large apothecia that are almost always present. A close relative of this lichen, the elegant sunburst lichen, was sent into space and exposed to ultraviolet radiation, cosmic radiation, and the vacuum of space for a year and a half.  When it was brought back to earth it grew on as if nothing had happened, and that’s why many believe lichens are virtually indestructible and are therefore as immortal as any earth based life form can be.

Some lichens prefer growing on smooth barked trees but others don’t seem to care and will form themselves to whatever shape the bark they grow on happens to have. What I think is a rosy saucer lichen (Ochrolechia trochophora) had done just that and was bowl shaped, but still happily producing spores.

Shrubby little beard lichens are fruticose lichens, and fruticose lichens have upright or pendulous branches. I think this one is a bristly beard (Usnea hirta.) Though it grew on the shadier side of a tree it was caught in bright sunlight, and I’d guess that it must get an hour a day. One way beard lichens reproduce is by fragmentation. Pieces break off and are carried by the wind or maybe animal fur to another spot to colonize. There are many of these high up in the trees and they come down, often still attached to the branch they grew on, during a good wind. I’ve found as many on the ground as I have on trees.

This is an extreme close up of a different beard lichen showing its granular soredia, which are another means of reproduction. A soredium is a tiny granular ball of fungal hyphae and algal cells. They can grow on the body of the lichen or on its margins. No matter what living thing you find in nature, it’s always about the continuation of the species, and the drive to survive seems very strong in all of the things I see.

I think this lichen is a powder edged ruffle lichen (Parmotrema stuppeum) because of its uniform gray color, broad rounded lobes with erect edges, and soralia on the lobe edges. Soralia are groups of soredia meant to fall or break off a lichen and are used as a vegetative means of reproduction. They are what makes this lichen’s lobe edges look like they were dipped in powdered sugar. This lichen also has dark brown to black undersides but they aren’t seen in this photo. It was about as big as a penny, or about 3/4 of an inch across.

Some lichens might look like they have little spiders on them, or maybe as if they had been carved with a pocket knife but no, the squiggly lines are the apothecia of the script lichen (Graphis scripta.) This lichen prefers trees with smooth bark and, from what I’ve seen, only produces spores in winter. You can walk right by a tree full of script lichens in summer and see only grayish spots with no apothecia at all. In fact many lichens seem to prefer winter for spore production and I’ve never been able to find out why.

Beautiful in its simplicity is the maple dust lichen (Lecanora thysanophora.) Plain and undressed without the fussiness of other lichens, it makes me think I could just stand and stare at it, warmed by its calm, clean lines. But how does it reproduce? I’ve never seen any reproductive structures of any kind on it so I had to look it up. The answer is that it does have apothecia, but very rarely. It also has “a thin patchy layer of soredia,” though I’ve never noticed it. The white fringe around the outside is called the prothallus and using it is a great way to identify this lichen, because from what I’ve read there isn’t another that has it.

I hope you’ll go out and look at the trees in your neighborhood. You might be very surprised by what you see.

I find myself inspecting little granules as it were on the bark of trees – little shields or apothecia springing from a thallus – such is the mood of my mind – and I call it studying. ~ Henry David Thoreau

Thanks for stopping in.

 

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