Thursday, March 26, 2009

A little rain

A little rain is falling on the mountain this morning. Very little, actually, and not nearly enough to impact the nearly 5 inch rainfall deficit. Still, it’s enough to likely end the red flag fire warning that the area is under currently. At least I hope so. This is certainly the first time I’ve seen one of those in March.

In any event, the overcast skies made it too dark to take a photo this morning, so I am posting one I took on Monday evening. Today’s photos is a lichen. Pennsylvania has over 400 species of lichens, I’ve read, but I’m not really able to identify many of them. Sometimes I think I can identify the family, but further investigation often makes me doubt even that much.

What I can tell you is that a group of small trees in this one spot are pretty much covered with this particular lichen. I am thinking this is one of the so-called green shield lichens, which are both common in my area and commonly grow on tree bark. If so, then this is not a plant. Green shield lichens are a combination of a fungus and either an algae or a photosynthetic bacteria.

Like all lichens, they tend to be sensitive to pollution, which is why they are not commonly seen in urban areas. However, that said, this particular lichen family is apparently at least somewhat less sensitive than most. They are said not to harm the trees on which they grow.

I suspect this is flavoparmelia caperata, the common green shield lichen. This variety likes clinging to tree bark, but will also grow on rocks, and the round or oval rosettes are typical. The surface of the lichens gets greener when wet—that’s the algae part migrating to the surface.

Maybe it will be greener tomorrow. I'll have to check.


The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

The rain here fizzled. A fews drops; not enough to matter.

One of these days I'm going to tackle lichens…one of these days. Right now, I'm pretty confident in stating that green stuff of the tree trunk, rock, fencepost, old barn siding, etc. is lichen. Sometimes, I think a little knowledge is better than a lot.

Carolyn H said...

Griz: I like lichens. I just don't know that much about them. I find it easier to learn first about the "big" things like animals and birds, then butterflies and other cool bugs, wildflowers, etc. Fungus and mushrooms are neat,too. I guess that means that I've finally reached the lichens--at least until the spring arrivals really get to rolling in.

Carolyn H.

Jeff said...

Always nice to see a nice photo from our area. I participate in the Skagway to Whitehorse road running relay race. Running up the hill always brings to mind how hard it was to carry the gear that those folks were required to bring. Makes running up it carrying only oneself seem like pretty light duty. Highlight of this years race was hours of northern lights. Thanks for the photo.