Lichenomphalia Umbellifera

Day 169: Lichenomphalia umbellifera fruits largely on decaying wood, inclining the casual lichenophile to dismiss it as an LBM ("little brown mushroom"), and although its finely grained, thin thallus is frequently concealed beneath mosses or other lichens as in the photo on the left, its dark pea-green colour is a clue to this species' true identity (immediately behind the fungus in the righthand image). It is one of very few lichens which exhibits a "mushroom" when it is in fruit, i.e., it is a basidiomycete as opposed to an ascomycete.

"There she goes again," you say, "using those big words. They scare me." Okay, let's break this down. Both fungi and lichens produce spores in specialized structures. Fungal spores are contained in basidia (singular, basidium). On the other hand, most lichen spores come from a similar structure known as an ascus (plural, asci). In the case of Lichenomphalia umbellifera, it reproduces like a fungus, but in its greater aspect, it has all the earmarks of being a lichen.

The fungal body emerges as a warm tan umbrella-shaped cap on a slender stipe. These age to white quite quickly, and turn up at the edges, the better to disperse the spores. They are fairly common in the Pacific Northwest.

Lichenomphalia Umbellifera

Day 142: You could be excused for thinking that this is a mushroom, but in fact it is the fruiting body of a lichen. Lichenomphalia umbellifera may be listed in your handy-dandy field guide as Omphalina, but that taxonomy is now considered out of date. Lichenomphalia is unusual among lichens in producing this type of fungal outgrowth. Most fertile lichens form apothecia in which spores are encapsulated within asci (saclike structures) as opposed to spores contained in basidia along the gill margins as is the case with Lichenomphalia. The thallus (body) of Lichenomphalia is comprised of small granules or flakes of the alga Coccomyxa. It can be seen in the photo as the pea-green crust on the rotting wood. Viewed from the bottom, the gills of Lichenomphalia will be seen to be decurrent (i.e., running down the stipe) and widely spaced, looking ever so much like a faerie's umbrella. This lichen is fairly common in the damp forests of the Pacific Northwest.

Lichenomphalia Umbellifera

Day 151: Yesterday, we talked about an ascomycetic fungus (i.e., a fungus which reproduces like a lichen), so today, we'll switch it around and talk about a basidiomycetic lichen (i.e., a lichen which reproduces like a mushroom). I told you this was a confusing field. Now you should have a better grasp of what I meant.

Now as you know, lichens are a symbiosis of fungus, algae and yeast. The algae come in two forms: green algae and cyanobacteria ("blue-green algae"). They are the photosynthetic partner in the ménage à trois. One type or the other is always present in a lichen, and is generally obvious in the colour even though some orange and yellow lichens might make you doubt my word. This is germane to the discussion, as you'll see shortly.

You're walking down the trail, looking for cool things, and your eye is caught by a cute little creamy white or tan mushroom growing out of an old stump. It looks like a little umbrella. You can see that it has gills if you look at the underside of the cap, so your immediate assumption is that it is a fungus. You're only partly right. Lichenomphalia umbellifera produces a fruiting body which resembles a mushroom in more ways than just visually. Its spores are produced externally by basidia, specialized cells on the margins of its gills, as opposed to most other lichens whose spores are produced in internal asci.

Now you're asking, "But what makes this a lichen? It looks like a mushroom to me." That's because you're not looking at the whole picture. The thallus (the main body) of Lichenomphalia is that pea-green and eminently algal substance coating the wood from which the "mushroom" grows. Fruiting body and thallus are parts of the same whole: a basidiomycetic lichen found fairly commonly on decaying stumps in the Pacific Northwest.

Things are not always what they seem to be at first glance.

Lichenomphalia Umbellifera

Day 140: Day before yesterday, I was feeling so ancy that whenever I stuck something in the microwave (a cup of coffee, my dinner), I jogged in place until the cooking/heating was done. The idleness first forced upon me by flu/pneumonia in January has been compounded by icy roads and snow in my driveway for the last two weeks, so I resolved that at the first opportunity, I would get out on a trail and put some miles on my feet. My strength needs rebuilding, but I managed six miles in just over two hours, although on terrain with very little elevation change. My goal was a rock beside a gate, on which a nice colony of (presumably) the lichen Dibaeis baomyces grows; however, it was not as lush as I'd hoped. I was despairing of finding a "blog shot" until on the return and in different light, I found a log lush with Lichenomphalia umbellifera. This is one of the few lichens which has a basidiomycete as the mycobiont, and although rare elsewhere, is fairly common in its PNW/arctic range. The squamules which appear on the log in this image belong to the skinny Cladonia spires. The thallus of Lichenomphalia is the darker green, finely granular crust on the surface of the wood.

Yes, I Said Lichen

Day 181: The taxonomists have struck again. Only recently renamed Lichenomphalia umbellifera (formerly Omphalina umbellifera) is one of the most unusual lichens you may encounter. Wait, did you say "lichen?" Yes, I did. It is one of very few species of lichen which carries out its reproductive process in the same manner as a mushroom, i.e., with spores which grow out out of cells (basidiomycetes) rather than being contained within them (ascomycetes). The thallus (vegetative body) is actually the pea-green crust you see on the wood. The "mushroom" is the fruiting body. For once, I applaud the taxonomists. Now perhaps with its new name, this LICHEN will get the respect it deserves and will no longer be dismissed as "that little tan mushroom."