Lichen Workshop Review
By Adrienne Lilly
In the Classroom:
Visiting Lichenologist, Toby Spribille, began with a basic introduction to the lichen and its world. The board was covered with drawings of the thallus, ascus and apthecium and as he spoke he drew more illustrations demonstrating the biology of the lichens.
Lichens are made up of two and sometimes three organisms. There will always be the fungus, which gets most of the credit when it comes to naming, and then there will be green algae and/or cyanobacteria. The alga that is found in the lichen is not found outside that specific relationship. They occur as individual cells of green algae within the fungal tissue, in our example it was right below the upper cortex of the thallus. The cyanobacteria, a much smaller organism, do not have a nucleus like the algae.
The sex lives of lichens are quite varied. As a group they reproduce asexually as well as sexually, some even do both on the same plant. The asexual reproduction is usually in the form of soridia and/or isidia, which are small bundles of fungal and algae cells that protrude off the main body and start a new colony after being separated in various mechanical ways. The sexual reproduction involves fruiting bodies called apothecia and spores. There are countless combinations in the lichen world but knowing what to look for can help identify the lichen species.
The fungi of the lichen world are ascomycetes, another type of fungus, the mushrooms, are mostly basidomycetes. Lichen has the possibility of affecting land management decisions as they have been found to be excellent indicators of subtle environmental changes. Differences in the soil composition influence the species not only occurring on the rocks and soil but also on the trees and leaves.
One can differentiate the lichen in large part by the substrate on which they are hanging out. The minerals in the parent material of rock and soil create a basic or acidic environment that even influences the trees on which the lichens choose to colonize.
Then the field trip:
It only took a couple minutes for our leader to find his first samples about 15 feet from the car. All one needs is a red alder tree in the woods and perhaps a paper bag. We were even shown a nifty way to make a paper envelope just from a sheet of paper.
We were in search of samples from each of the 4 basic lichen forms:
Crustose – these are almost part of the substrate, cannot be separated from the bark or rock to which it is attached.
Scale – attached on one side only, small shell like lobes.
Coleus or Leaf – larger lobes, will have two distinct sides, usually with a hard attachment and hard lower surface.
Shrub – multiple surfaces, can be linear like lobes or even hair-like, difficult to distinguish top from bottom surfaces.
On our red alders we started with a crustose lichen which was a light colored oval or circle that appears to be part of the bark. Phlyctas argena was seen again later on some smaller conifers with smooth young bark.
A common leaf lichen was shown next, Pulmeria sulcata is gray on top and black on the lower surface, which looks almost hairy. The soridia are found in the cracks on the upper surface. One can actually slice this lichen and spot the layer of algae with the naked eye.
The color of lichens are often determined by acids found in their chemical makeup. We looked at Evernia prunastri, or staghorn which was yellowish green on the top and had a white underside. Usnic acid is commonly responsible for the yellow color such as this. There is a genus named Usnea which we see more of at our next stop.
Even though this was a favored substrate for our lichen hunter, we moved about fifty feet down the road to a small opening surrounded by some more mature hardwoods.
The next collection of lichens was hanging around on some trees at the edge of a small clearing. Toby showed us an example of the Usnea genus, a characteristic common to this genus is a strong central strand that can be seen by removing the outer cortex. Many of the samples were shrub (or hair) type lichens. There were at least two types of Bryorea, perhaps three. They were varying shades of brown and grey with long thin branching. Apparently this genus needs good stand ventilation for healthy growth. B. lonestres was a brown color with finer stems common in the branching. B. fermontii was identified by the deep pits at the base of the hairs, although that may take a well trained eye to see. B. capilaris was a lighter grey color.
One leaf type lichen that was found was Tuckermanopsis chlorophylla, a brown colored lichen similar to the appearance of Parmelia in that it has a distinct upper and lower surface. As we started to drift across the road into a mixed stand we saw another of this genus, T. orbetiata.
Young conifer stand
One of the most common lichens in North America is the Hypogymnia. It is white on the surface and characterized by hollow branches that can be closed or open at the branch ends. A common name would be birds-bone.
Platimatia glauca is called tattered rag or lettuce lichen. Again, it can be said to have a similar appearance to Parmelia but that is only at first glance. P. glauca is more upright but it still has a distinct upper surface that is grayish with a brown lower surface.
Many pinhead lichens were seen on the downed woody debris as well as some Cladonis sp. We found a great sample of Lobaria pulmanaria, it has a densely ridged upper surface and the lower surface has small whitish hairs. The younger conifers with smooth bark were a great spot to find Phlyctas argena. A crustose lichen that forms round to oval white marks on the trees.
Many of the followers were familiar with the wolf lichen, Letharia vulpine that was found. The folklore of its use to poison wolves was well known, which Toby said was partially due to the presence of the toxic volpinic acid. The type of branching can help determine the difference between L. vulpine and L. lupine.
The world of lichen is so new that a small lichen occurring on the needles of the fir trees, called foliacols, was just recognized in Idaho only two years ago. Toby was extremely excited to discover what appeared to be something new to him and began a collection frenzy while the rest of us decided to lunch.
After lunch we saw Parmelia sacsaties on a branch even though it is more commonly on rocks. Then we were off to Mineral Point for more lichens.
We walked out a bit to a dry and warm Douglas fir site. Toby described the Douglas fir tree trunk as paradise and said there could be as many as 25 species of lichen on that tree alone. We had a great discussion on the value of lichens towards a complete understanding of forest ecology, air quality and intrinsic value.
Some of us gathered around the tree and picnic table as others wandered out and gathered samples. A crustose lichen, Ochrolechia that will turn red with simple household bleach. Xanthoria found on nitrogen rich rocks. Schaereria dolodes, a brown crustose lichen with black apothecium, one of only two Schaereria that grows on bark.
Then the group started to hang out on a rock outcropping hundreds of feet above the lake. When asked what he saw on those few large rocks, Toby replied he couldn’t even count the number of different lichens located on those few square feet of rock as they were so abundant. He also explained lichens on rocks are less studied than other lichens.
There was a picture book example of Rhizocarpon geographicum, map lichen. We found Umbellcaria which was identified by one centralized holdfast (described as a belly button like structure). The U. phaia is a smoother species and the U. torrefacta has rhizomes that do not act as attachments. Other lichens mentioned were Ochrolecia upsalensis and Xanthoria polycarpa. Toby continued to focus on the rock lichens with a majority of the group but we eventually had to call it a day.
This is only a sample of all that was happening, Toby was constantly fielding questions and identifying samples. He was very comprehensive when talking about the samples . There was so much information to learn and absorb that we could have followed him through the woods for so much longer.
(in no particular order and not particularly complete)
Parmelia sulcata – powdered shield
Evernia prunastria – staghorn
Ramalina: has apothocea
Ramalina dulacerata – yellowish grey color
Bryoria: needs good stand ventilation
Bryoria capilaris – lighter grey color
Bryoria lonestres – brown color, finer stems branch
Bryoria fermontie – hairs deeply pitted at base
Tuckermanopsis: brown leaf lichen
Hypogymeiia fiscodies - birds bone fungus, white on top, hollow characteristics (similar appearance to parmelia.
Hypogymeiia tubolosa -
Platismatia glauca – tattered rag or lettuce lichen, similar to parmelia but more upright form, grayish upper surface and brown on the lower surface.
Cladonia: has golf club like structures that that are not apothocia (reproductive structures.
Lobaria pulmunaria – lung lichen, densely rigid upper surface, and lower surface has small whitish hairs, some species have cynobacteria instead of algae, and some species have all three components. (will turn greener when water added)
Phlyictas argena - crustose lichen common on forest trees, round or oval white to grey spots from
Pinhead lichen – common on standing/leaning wood