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Posts Tagged ‘Lichens of North America’

1. Stone Wall

We’ve had some warm weather here and that means that the snow is melting away from the stone walls. Since there are many miniature gardens growing on these old walls I thought I’d have a look.

2. Scattered Rock Posy Lichen

Right off I was drawn to a boulder with patches of bright orange all over it. They turned out to be scattered rock posy lichens (Rhizoplaca subdiscrepans); more than I had ever seen in a single grouping. The white pine needles in this shot will give you an idea of just how small these lichens are.

Observing the small size of lichens is a good way to get used to seeing the small and beautiful things in nature. If you want to see the magic in nature sometimes you have to stretch some, and that includes your eyes, so each year at about this time I start looking closely at lichens to get my eyes and mind back into “small mode.” I practice on lichens in the early spring so I don’t miss the tiny flowers, insects, fungi, slime molds, and other fascinating things that will come later on.

3. Scattered Rock Posy Lichen

The fruiting bodies (apothecia) of these scattered rock posy lichens surprised me by looking like a mass of orange sausages.  Usually they are flat and disc shaped like the one in the upper left corner of this photo, and I’m assuming that this is what they look like before they take on the disc shape. Each disc shaped apothecia is about .04 inches (1mm) across.

If you’re interested in seeing small things in nature and have a ruler handy, you might want to look at it now so you can become familiar with just how small 1 millimeter really is. Finding things that size on a rock or tree can be a challenge, and that’s why I have to retrain my eyes to see them each spring. It isn’t just the eyes though; it’s also knowing where to look and knowing how to “think small,” but they come with experience.

4. Rosy Saucer Lichen aka Ochrolechia trochophora

Lichen identification can be tricky. I found what I believe is a rosy saucer lichen (Ochrolechia trochophora) growing on stone but the book Lichens of North America says that this lichen grows on tree bark. A little further research on the website Images of British Lichens shows that it grows on tree bark or stone. Based on that information and the fact that I can’t find a similar saucer lichen that grows in New England, I’m going with rosy saucer lichen. Even though it has rosy in its name its apothecia can range from pink to orange, according to what I’ve read.

5. Cumberland Rock Shield Fruiting

I’m not sure how fast Cumberland rock shield lichens (Xanthoparmelia cumberlandia) grow but any lichen this big has to be very old. It must have been 10 inches across and there were several others that big nearby, so I think it’s safe to assume that these stones haven’t been disturbed in quite a long time. They were fruiting so they must be happy here.

Note: Canadian biologist Arold Lavoie has identified this lichen as a peppered rock shield (Xanthoparmelia conspersa). Arold pointed out that Cumberland rock shield doesn’t have any of the granular vegetative reproductive structures called isidium that can be seen on this lichen. Thanks very much for the help Arold.

6. Cumberland Rock Shield Fruiting

This is a closer look at the fruiting bodies (apothecia) of the peppered rock shield lichen. They are fairly common and always seem to be folded or deformed looking. They are also always orangey-brown or dark brown in color.

7.  Crater lichen aka Diploschistes diacapsis

I used to just pass by things that looked like white or gray crust on stones, but I stop and look a little closer now after finding things like this crater lichen (Diploschistes diacapsis). The lighter parts of this lichen make up its thick body (thallus) and the dark spots are its fruiting bodies (apothecia). Its common name comes from the way the apothecia sink into the thallus and look like tiny craters. Crater lichens prefer growing on calcareous stone and are a good indicator of limestone in the area. If you’re trying to find orchids or other plants that like lime laced soil, finding this lichen on the stones in the area you’re searching might lead you to them. I’ll be watching for it later on when I search for hepatica and spicebush.

8. Mealy Firedot Lichen aka Caloplaca citrina

Mealy firedot lichen (Caloplaca citrina) is a pretty little yellow to yellow-orange crustose lichen that likes to grow on wood or stone. The book Lichens of North America says that it is a very common lichen that rarely produces spores but this example seemed to be fruiting happily. The mealy part of its common name comes from the numerous granular soralia, which are used as a vegetative means of reproduction. They are meant to break off and start new lichens.

9. Mealy Firedot Lichen aka Caloplaca citrina

It could be that because mealy firedot lichens reproduce vegetatively they don’t feel the need to use energy in spore production but as this closeup view shows, this example was doing both. The tiny round objects that look like the suckers on an octopus are its fruiting bodies (apothecia). The shiny background in these photos happened because the stone was wet, so this lichen was getting plenty of water.

10. Contorted rimmed lichen aka Aspicilia contorta  Lichen

This is another kind of ‘ho hum’ white crusty lichen that doesn’t look very interesting until you get out your loupe or train your macro lens on it.

11. Contorted rimmed lichen aka Aspicilia contorta  Lichen Fruiting

The ‘boring’ lichens have taught me that if something in nature doesn’t look worth bothering with it was only because I wasn’t really looking at it, because there isn’t a single piece of nature that isn’t beautiful or fascinating in some way. The fruiting bodies of this contorted rimmed lichen (Aspicilia contorta) were as tiny as a pencil dot on a piece of paper but they were there, and I’ve walked by them hundreds of times without stopping to see them. Finally noticing them wasn’t a life changing experience but such an alien landscape is very beautiful to me and I understand a little more about lichens than I did previously. Observing the beauty of nature and gaining knowledge are never a waste of time.

12. Gray and Yellow Crustose Lichen

It seems that every time I do a post on lichens I have one or two that have me completely stumped, and this is today’s winner. Beyond knowing that it is a gray and yellow crustose lichen that was growing on granite, I know nothing about it. It’s another beautiful thing though, and eventually I’ll come across something similar in a book or on line that will get me started on the (sometimes long) trail to its identity.

I should say for those new to this blog that I am strictly an amateur at lichen identification. I don’t have a microscope, chemicals, or any of the other tools that lichenologists use but neither do I guess at lichen identities. I use the tools that I do have and often spend many long hours trying to identify these little beauties. Though I’m fairly confident of a lichen’s identity before I put it into a post, you should be aware of my limitations and should not bet the farm on what I believe it is. If you happen to be reading this and know of any mistakes I’ve made I’d be happy to have you correct them. When that happens we all benefit.

For lack of attention a thousand forms of loveliness elude us every day. ~Evelyn Underhill

Thanks for stopping in.

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