As obsessive readers of this blog may recall, I pollarded my neighbors’ mulberry tree in November. This involved pruning off several dozen long, less than two-inch thick vertical shoots. I had probably a hundred such branches when I was finished, some of them about ten feet long. Becky, being the best wife a guy like me could possibly hope for, bought me a big honking electric chipper shredder a year ago, and so I spent a couple hours that day turning those branches and most of their attendant leaves into about a cubic yard of chips. “That’s enough for the day,” I said to myself as the shredder jammed on the last bit of green wood. “I’ll wheelbarrow the chips out to the compost pile tomorrow.”
The chips, of course, are still in the driveway. First the wheelbarrow turned out to have a flat tire, and then there was something good on television, and then it rained for a week and then I was out of town and anyway they’re still in the driveway.
What with our living with a rabbit and a guinea pig, we have an abundance of shit around the place. Browsing through a mail-order catalog of mushroom spawn last year, I decided to buy some inky cap mycelia to toss into the compost pile. Inky caps do well in substrates of manure, and they like wood chips as well, and I planned to put the pollard chips atop the small animal poops to provide an ideal growing medium for the mushrooms.
Inky caps, often called shaggy manes and known to taxonomy nerds as various species of Coprinus, are interesting critters. They’re one of the more common and easily recognizable mushrooms around, what with their characteristic behavior of magically turning into black slime. The spawn I bought was of the species Coprinus comatus, but there are a bunch of them, at least until the taxonomists decide to split the genus up into a bunch of new ones.
A mushroom is just a reproductive organ, only a small part of the typical fungal organism, and many fungi don’t even use them. Many fungi are unicellular, like yeasts, and reproduce by division or budding. Multicellular fungi such as my inky caps are called filamentous fungi. The bulk of an individual fungus is in its mycelium, a massive network of filaments — hyphae — that penetrates and consumes the substrate on which the fungus grows.
The hyphae in some more primitive fungi are just plain hollow tubes, through which cytoplasm moves back and forth, carrying nutrients and water and hormones and the like throughout the mycelium at a dizzying four or five inches per hour, pushed by little “muscles” made of a contracting protein called actomyosin.
Here’s a little fact that blew my mind when I first thought about it for a while: the actomyosin transport system can push fluid through a hyphal tube in both directions at the same time, by setting up discrete streams in different sections of the tube. Imagine being able to ship your drinking water into the house in the same pipe that drained your wastewater!
The hyphae of “higher” fungi have little walls like checkpoints along their length (roughly similar to the phloem sieve elements in many vascular plants, for those of you who remember your high school biology.) These restrict the flow of cytoplasm only slightly, but keep nematodes and the like from biting off an end of a hypha and sucking the mycelium dry. The walls, or septa (higher fungi are also called septate fungi) are made out of chitin and a few other tough substances. Chitin is what insect exoskeletons are made of.
That’s another mindblowing fact in the “kinship of all life” category, by the way: plant cell walls are made of cellulose, and fungal cell walls are made of chitin, which indicates that fungi are related to both plants and insects, which means my pollarding that mulberry was basically performing cosmetic surgery on a distant cousin. Woodsman, spare that tree!
Mushrooms are what mycelia use to make baby mycelia. A mushroom is basically a spore factory, and most mushrooms, like the portobellos you ate last night, produce those spores from their gills, those little grooves on the underside of the cap. Inky caps’ caps are very narrow and long when they first emerge, which would tend to impede spore dispersal. Coprinuses get around this by liquefying their caps from the bottom up, thus dripping sticky black juice all over everything and more importantly getting the cap margins out of the way of the later-maturing spores closer to the apex of the cap. The spores blow around, land on another suitable surface, and grow new mycelia while we are distracted getting black ink stains out of our clothing.
This habit is probably the main reason people don’t eat more inky caps: they’re supposed to taste pretty good, but you kind of have to catch them just at the right moment before they decompose. That’s probably a good thing in the main, as the shrooms contain coprine, a substance very much like the old drug Antabuse. If you don’t consume any alcohol for about a week after eating inky caps, you should be fine. But crack a beer the next day by mistake, and bam: an emergency-room caliber hangover. Unfortunately, some people claim that smelling vanilla extract or using mouthwash are likely to provide enough blood alcohol to make the coprine do its stuff.
I might try to eat them someday, and I’ll let you know if I do so that you can avoid smelling my breath for the next week. Which is probably a good idea in any case. But I was mostly interested in the Coprinus as a garden tool: a way to turn lots of compostables into rich garden soil without doing any actual, you know, work. If I cultivated a nice big bunch of Coprinus hyphae in the compost pile, I’d actually have a reason not to go out and turn the compost every week: why chop up a critter that’s doing all that hard work for me?
Despite my leaving the mulberry chips out of the compost pile the inky caps prospered and eventually colonized the entire pile. Flushes of mushrooms have emerged, grown, deliquesced, and faded. The pile occupies one corner of the bin: I’ve started building a new pile and the Coprinus has already started to take hold there. In about a year, with any luck, I will have distributed the finished compost around the garden and thus sowed Coprinus in the vegetable beds, the orchard strip, and the herb garden near the shed. A garden is incomplete, I think, without mushrooms in it, and the presence of mycelia is often a boon to green plants: fungi can make nutrients available that the plants would otherwise have missed.
And I may not even have to move the compost to get there. A hundred feet away, on the other side of the house in the middle of the driveway, the mulberry chip pile has started growing its own crop of inky caps. The mycelium started in mid-pile, and there’s now a patch of partially digested wood there, surrounded by a ring of icky drippy mushrooms slowly working its way to the edges of the pile.
I don’t know whether spores drifted from the compost on the wind, or hitchhiked from out back on a garden tool, or whether this might be a strain that was already in the neighborhood before I had some shipped from Oregon.
All I know is that I now have another reason not to move those chips for a while longer.