‘Tis the Season for a Multitude of Mushrooms By RON SULLIVAN Special to the Planet

Tuesday January 10, 2006

Instead of trees this week, I’m going to talk about something bigger: mushrooms.They’re popping up all over since the major rains, and in bewildering variety. For pete’s sake, don’t be inspired to go on a mushroom-eating binge because they look so pastry-pretty. The old saw goes; “There are old mushroom hunters and there are bold mushroom hunters, but there are no old, bold mushroom hunters.” Think agonizing death in a pool of your own various wastes. Think liver transplant. Think never being able to have another beer if you do survive. Got that?  

But look at them! 

They’re gorgeous. I’ve seen them in classic mushroom shapes, in banded fans, in brilliant glistening globs, in wavy combs, and in the rather startling shapes that give rise, so to speak, to the species name of one, Phallus impudicans, commonly known as the stinkhorn.  

They’re colorful. They come in white and gray and various shades of brown and russet, in maroon, burgundy, scarlet, orange, yellow, even blue. They’re ubiquitous, too. There’s a lemon-yellow cluster right now in my dining room, emerging jauntily from the base of the Yule tree’s pot. (It’s a live redwood that lives in the backyard most of the year.) We’ve entertained clusters of Peziza domiciliana in the bathroom caulking; the species’ major habitat is the North American bathroom. Once, though, we had it growing in the floor carpet of our pickup truck.  

When you see them popping up on the grass, mushrooms are telling you two things: it’s wet—either poor drainage or just constant rain—and there’s decomposing plant matter there. This is a problem if it’s your oak tree and the fungus is Armilliaria, but not so much if it’s just some random instrument of composting on the wood-chip mulch. 

They’re not plants. It’s not just that they lack chlorophyll; more basically, they have cell walls like plants (rather than cell membranes like us animals) but the walls are made of chitin, like, say, shrimp shells. Fungi are their own separate “kingdom” (and there are more of those than you’d think, several all-unicellular).  

What you see above ground is just the reproductive organs, and they reproduce in dizzyingly complex fashions; four or five “genders” can be present. (Actually, I’ve seen the allegation that mushrooms have 36,000 sexes, but I’d want to see some definitions.) The spores they shed push out mycelial threads that can mate with other threads—sometimes with fertile results, sometimes not—in several ways. The spores, like our ova and sperm, have only a half set of chromosomes—they’re called “haploid.” They can join with one or more other threads in various ways, in effect giving some offspring three parents: two for the chromosomes and another for the cytoplasm, the part of each cell outside the nucleus.  

When two compatible haploid spores meet, they effectively merge into one cell that still keeps two nuclei. These can split into two cells with four nuclei, and so on. This gives the organism an advantage—it can grow faster, since instead of stretching one cell over a gap it can just multiply cells.  

So you get those fuzzy patches … Have I mentioned that the weird science experiments on the leftovers in the fridge are generally fungi too? Anyway, these patches can grow rapidly, meet other compatible fuzzy patches, grow “clamp connections” between themselves (this gets kinkier as you learn more about it) and complete mating.  

Keep the kids out of the fridge! Better be ready to have a family discussion about what’s happening on the mulch out back, too. 

There’s a great account of this on the Web at the Shroomery site—www.shroomery.org—and I take the blame for any errors here in trying to fit that into my space.  

But did I say “something bigger” at the top? Yes. Those toadstools and fairy rings are only a small part of the fungus they represent. The actual organism is below ground, spread out as a net of myceliae. There’s an Armillaria in Malheur National Forest in eastern Oregon that’s three and a half miles across, covers 2,200 acres, and is at least 2,400 years old. It might be 7,200 years old. That would make it the oldest known organism on Earth, as well as the biggest.