Last week I was in western Maine, enjoying a last blast of
summer vacation. Hiking through the mixed woods around Flagstaff Lake, I was
amazed by the abundance of fungus growing in the woods. We saw several
different coral fungi, puffballs, earth tongues, amanitas, slime molds and many
different kinds of mushrooms. Late summer and fall are peak times for fungal
fruiting activity, as long as there is sufficient moisture and we were clearly there
at the right time. Fungi are very ephemeral, responding to temperature and
humidity, and the species you see around you fruiting on the forest floor
change from week to week and even day to day.
The species that made the biggest impact on me however, was
the lobster mushroom, otherwise known as Hypomyces
lactiflorum. They were everywhere, huge and bright orange and erupting out
of the duff and leaf litter. They are called lobster mushrooms due to their
orange color, looking something like the orange of lobster meat, or cooked
lobster shells, and they are reportedly edible, though I doubt they bear any
culinary resemblance to lobster.
The lobster mushroom’s claim to fame or dirty secret is that
it isn’t really a mushroom at all, not in the conventional sense anyway. What
we see and call a lobster mushroom is actually a mushroom of one of two common genera
that has been parasitized by the Hypomyces
lactiflorum fungus. Hypomyces has
no shape of its own, its mycelium (or generic fungal fibers found in soil
everywhere in the forest) live in the soil among the mycelium of its host
species. When the host species fruits, the term for creating a mushroom, Hypomyces invades and uses the host’s
mushroom for its own purposes. And what
is the purpose of a mushroom? It is the reproductive structure of many kinds of
fungi. When the mycelium of two separate fungal individuals of the species meet
in the soil, they exchange genetic material and the resulting mushroom is
simply the above ground tissue where the spores
(which are analogous in many respects to plant seeds) are formed and
then released into the air, which is the medium in which they are dispersed.
For some reason Hypomyces can’t make
a mushroom on its own, so it uses someone else’s. If you look closely at a
lobster mushroom, you will see the tiny little sacks that are the fruiting
structures of Hypomyces, they cover
the surface of the lobster mushroom, and that surface area is what Hypomyces is after. The host fungus also
undoubtedly provides nutrition to the parasite, so this is a case of a fungus
eating another fungus as well as the story of a reproductive service
unwillingly provided by one fungus to another. 
The victims of this attack are fungi in the Lactarius and Russula genera. They are both very common in the forest and include
hundreds of species. Both form mycorrhizal or mutually beneficial relationships
with most trees species as well. In the northeast, Hypomyces typically parasitizes Russula
brevipes and Lactarius piperatus.
We are coming into peak mushroom season. I encourage you to
get out on a fungal foray of your own. Go for a walk in the woods and take your
time, bring a field guide and a camera and spend the afternoon exploring the
diversity that can pop up overnight, and disappear just as quickly. And it must
be said, you have to be careful. Just because lobster mushroom is named after a
food, that doesn’t necessarily mean it is edible. Remember it’s a parasite, and
you can’t identify the host once its been parasitized. There are people out
there who can teach you about wildcrafting edible mushrooms, I am not one of
them. So please, due diligence is in order. Fungal appreciation is a life long
pursuit, I am enjoying the state of “beginners mind” I find myself in, where
the discovery and identification of a common species brings excitement and joy.
I hope this fall, you will join me in this simple pleasure.
References:
George Barron’s Mushrooms of the Northeast North America,
Lone Pine Press 1999, one of my favorites, nice photos.
David Arora Mushrooms Demystified Ten Speed Press
1979, 1986 The definitive mushroom book for most of us! Pacific Northwest
centric, but still useful. Dense, and lacking lots of pretty pictures (most are
black and white). Clearly kooky author.
Lawrence Millman Fascinating Fungi of New England
Kollath and Stensaas Publishing 2011
Tom Volk’s webpage on Hypomyces:
