Slugs & Mushrooms


Ariolimax columbianus, (Pacific Banana Slug)

by Brady Raymond

Let’s talk about Slugs.


Yeah, slugs.


‘Cause slugs are cool.

I guess I’m writing this article because slugs are cool, and a little gross by most human standards but so are mushrooms to many folks, but us mycophiles seem perfectly delighted by their curious ways. So why not give slugs a chance? Plus, I saw more slugs in the last couple of outings than I did mushrooms, and that’s ok because in my opinion these gooey gastropods are a good omen. When you see slugs it means conditions are progressing in a manor which will facilitate the growth of fungi and that condition, is moisture.


Arion rufus, this species also occurs in a lighter brown, orange and a jet black variety.  Notice the pneumostome on the right side of the mantle, the hole by which the animal breathes.

Malacology is the study of Molluscs which is the phylum of animals that include the classes Polyplacophora, Aplacophora, Bivalvia, Scaphopoda, Monoplacophora, Cephalopoda and Gastropoda wherein slugs and snails reside. Malacologists estimate the number of land gastropods to approach 35,000 species worldwide. That is more than all the vertebrates combined excluding fishes. Slugs and snails are quite well adapted to their varied environments, which is everything from temperate to tropical forests, alpine tundra, grasslands and deserts.

You see, slugs and snails are prone to drying out, and like mushrooms seem to be absent from our yards and favorite hiking trails during the dry summer months as they have no doubt sought out the moist crevices under logs or burrowing down deep into the duff and entering an aestivate state. But when the rains do come again, in this case the impending fall they seem to be everywhere. It is hard to miss a nine inch plus Ariolimax columbianus, more commonly referred to as the Pacific Banana Slug (pictured at top) crossing a trail this time of year, and even harder to miss the twenty you’ll see after it in just a short distance. It’s not uncommon to avoid stepping on one only to feel the squish of another you didn’t see under the other foot.

The biology of these creatures is is incredibly interesting, yet not for the faint of heart.  There is an excellent field guide published by the Royal BC Museum entitled;  Land Snails of British Columbia, by Robert G. Forsyth.  I recommend it highly and would assume for the most part to be an accurate guide for Washington as well.  Mycophiles who are familiar using keys to figure out mushrooms will be at home in understanding how to use this book  but like mushrooms certainty in identification sometimes requires effort most just can’t achieve as a layman.


Arion rufus, these stately slugs can reach lengths of 7in.

I could go on about slugs but this is a mushroom blog and the title was Slugs & Mushrooms, enough slugs you say, get to the mushrooms. Okay, okay and now for the mushrooms. The last few days Erin and I have been out and about looking for mushrooms, surely we were bound to find something more than just a conk, we had quite the downpour up here in Marysville a few days earlier and we had a feeling, you know the one. So we checked out a local park and what would you know right on the side of the trail was a young Phaeolus schweinitzii, although rather common it is a prized find for a would be mushroom dyer. We decided to leave this small young specimen and check back in a week or so out of curiosity as to its growth habits. But the thought was etched in our minds, where there is one there are more.


Slime molds were abundant and plenty on this trip.

We had the idea that if we could just get up a thousand feet in elevation, maybe two, we would hit gold, finding enough of this polypore to dry and store, to maybe even teach a dye workshop in the future if other folks have an interest in these things. But we encountered the same story as above, we found a beautiful young specimen at one of our regular spots yet it was a little to young. We just couldn’t bring ourselves to pick it. We decided to check back in a week or so and see how this one would progress as well.  So we ventured on, not sure of what we would find.

After making a few more stops and not finding much of anything save that of a few Mycena and some small waterlogged Sulfur Shelves we were wondering if the two we spotted were early season flukes. The conditions seemed good, plenty of moisture, lots of slugs but the temperature was a bit warm, and many mushrooms do like things a bit on the brisk side. We stopped again, I scrambled up a steep but not overly high hill where last year we had found a Sparassis, a number of Chanterelles, a few Lobster mushrooms if memory serves me and of course a nice big P. schweinitzii. My intuition told me it was still to early for the edibles but I had that nagging feeling there was a polypore somewhere up there with my name on it. After poking around a bit and trying to focus my efforts around the base of Doug-Firs both the living and the dead, I was handsomely rewarded with a prime young find of P. schweinitzii, still small but bigger than the others. I without hesitation unsheathed my blade and gleefully harvested what was in front of me (pictured below).


A young and still fuzzy Dyers Polypore.


Moldy Hedgehogs, bummer.

As the old Subaru climbed, Doug-Firs gave way to a Hemlock dominated forest and I wondered if maybe we would be greeted by a change in the fungal scene as well. And we were, there was a smattering of Russulas, a handful of Hedgehogs, a single large Bolete and one Gomphus I think G. kauffmanii.  But what this diverse group of fungi all had in common was desiccation of age, and a moldy camouflage which made for slightly  insidious photos.

Sea Level Romp and Haul


It’s tough to see but there is a Pacific Banana Slug underneath, eating away with its radula at the pores of this poor polypore, there was a smaller unidentified slug present too.

We rested the next day, wondering where we should go next, and then we got a call. Some family was staying out on the shores of Whidbey Island and asked if we wanted to come out and stay for a night. We accepted this invitation and started thinking of places we could look while we were out there.

The next morning we headed out, we drove around, up to Deception Pass and would continue home the next day via the Clinton ferry. We hit up a couple of spots we knew and found one small specimen, a little deterred we arrived at our destination and talked mushrooms over a burger and some beer. We would find at least a couple the next day, we were sure.

After getting around and packing the car we were on the road just before eleven, it was turning out to be a nice day and are hopes were high. We got to our spot, it had been productive for us in the past, for a few different species including P. schweinitzii. There is not much to the story after that, within five minutes of walking around we had found our first specimen, then the next and yet another, they seemed to get bigger each one we found. There was no shortage of slugs either, those little gross but good omens. We figured we had enough, for today at least. There is still the task of dehydrating, thankfully cleaning isn’t as necessary for these mushrooms, the dye pot doesn’t seem to mind a few twigs, leafs and maybe an unfortunate slug or two.

So if your interested in dyeing with mushrooms, now is a good time to start looking for Phaeolus schweinitzii also known as the Dyers Polypore.  It is a great species to start with as they are easy to find and produce vibrant, earthy greens and yellows, depending on how you pretreat the yarn.  To learn more about the process check out Erin’s articles, Mushroom Dyes Part 1 & Part 2 and stay tuned for Parts 3 & 4.