Lobster Mushrooms - An In-Depth Overview

Written by Adam McCrae

Disclaimer: Foraging mushrooms, while an exciting and fun activity, is not a game. Never eat any mushroom that has not been 100% identified as edible by someone qualified to do so. Always cook wild mushrooms thoroughly, and try a very small amount your first time eating a species to test for personal intolerance. (Eat 1-2 bites, wait 24 hours). Do NOT trust any app to ID mushrooms for you.

Three lobster mushrooms of varying color/ages. Generally speaking, the lighter the mushroom, the younger it is.

Lobster mushrooms: one of nature's quirkiest and most awesome combinations of fungi! These stunningly bright and edible beauties are the result of a host/parasite relationship in which the parasite Hypomyces lactifluorum attacks non-toxic members of Russulaceae, specifically the host Russula brevipes (Short-Stemmed Russula).The resulting fruiting body shows no gills of the original white mushroom, and the entire underside becomes a smooth/pimpled bright orange surface that produces the spores of the parasite instead of the host.

While considered edible and choice when in good condition, older specimens of Lobster Mushroom can also be used as a natural dye.

In this blog, we'll be going over pretty much every aspect of lobster mushrooms I can think of! We'll be diving deeper into that host/parasite relationship, discussing where to find them, giving detailed info on their many morphologies, their multiple uses, and pretty much attempting to get all the things I know about them finally written down in one place. 😅

Let's get started with some general facts, then we'll jump right into their identifiable features.

Lobster Mushroom General Facts:

• Bright orange fruiting bodies are the result of Hypomyces lactifluorum attacking non-toxic Russulaceae.
• No toxic host has ever been witnessed. No poisonings have been reported due to a toxic host.
• These fungi are often prone to *very* odd formations. The parasite infects the mycelium of the host underground, and the resulting mushrooms are often warped, bulging, blobby or even completely upside down! (see pic)

Lobster mushroom growing upside down, with the hymenium (spore producing surface) pointed toward the sky.

• With their bright coloration and distinct features, lobster mushrooms are fairly difficult to misidentify and generally considered a good mushroom for beginners to learn to forage.
• Lobster mushrooms are edible, considered choice, and are sold commercially in the USA.
• Lobster mushrooms have not been cultivated with traditional methods. The host/parasite relationship complicates an already difficult process, and necessary tree association for the host complicates it further.
• Since they cannot be cultivated, all lobster mushrooms are therefore harvested wild.
• There *are* many anecdotal stories of "seeding" patches of Russula with chunks of old lobster mushrooms in an attempt to make a new patch of lobsters. I have done it with success.
• Lobster mushrooms do not have a significant amount of poisoning cases, but individual sensitivities do happen, and some people cannot tolerate them.
• Older specimens have the distinct odor of dead fish.
• Lobster mushrooms can be *very* prolific, with relatively small areas producing many, many mushrooms. Since these mushrooms often weigh a pound or more, they can add up fast. Feel free to be very selective when picking for culinary use, if they are abundant.

The cleaned top of a Lobster Mushroom cap, showing pitting/cracking and other oddities.

Lobster Mushroom Features:

• Cap: 2-12"+ across. Top often warped, cracked, bulbous, showing hymenium growth/rosecomb. Lacking gills on the underside (thick ridges where gills *tried* to form sometimes visible). Cap surface prone to compacting with dirt, especially when wet. Usually roughly circular in shape from above, but strange variations are common.  Variations of white/light orange on both sides when young, proceeding to red and then purple with extreme age. Light colored flesh often shows through cracks in the top of the cap. 

• Stem: 0-4"+ across, 0-6"+ long. Generally short and thick compared to the cap. Can be missing entirely, with just an attachment point of mycelium but no actual stem. Usually the same color as the underside of the cap, and appears to be covered in the same spore-producing surface. 

• Overall Fruitbody: Large, usually distorted. Most specimens will resemble a rough funnel shape from the side. They can also present as amorphous blobs, have a rough "clam shell" shape, or invert entirely. Parasite/host relationship provides many odd specimens, even growing together or stacking on top of each other at times! (see pic)

• Flesh: White and very firm when young, similar to the texture of a potato. Becomes softer and discolored with age. Often prone to the larvae of fungus gnats, which will dig tunnels starting at both cap and base of these fungi. Can regrow orange color when interior surface area is exposed (cut).

A lobster mushroom, growing out of the top of another lobster mushroom.

Lobster Mushroom Uses:

There are two ways that lobster mushrooms get used most often. The first is culinary use, as a choice wild edible for the table (after cooking). The second is for use as a natural dye! That bright orange exterior can be used to coax beautiful colors into a variety of materials and fabrics.

Lobster Mushrooms For Culinary Use:

• Young, lighter colored specimens (white to orange, not red or purple) are considered choice for eating.
• High quality flesh should be white and quite firm.
• Watch for fungus gnat larvae that tunnel from both top and bottom. Examining the cross-sections that naturally occur as you slice the mushroom will expose tunnels. (Eating larvae will not harm you, but many folks find them unpleasant to see and their tunnels can increase the speed at which the mushrooms degrade)
• Older/darker sections and larvae tunneling can be removed if the rest of the mushroom is of high quality.
• The firm texture and interesting flavor of this mushroom leads some people  to dislike it with "traditional" preparations, i.e. sauteed in butter and garlic.
• I hear great things about butter-poaching, or using a recipe such as Forager Chef's vegetarian take on Crab Cakes using these fungi: Lobster Mushroom Latkes.
• Using water pressure to remove compacted dirt makes cleaning a breeze, but only clean mushrooms that you're getting ready to use, don't store mushrooms that you have cleaned with water. You can see my lobster mushroom cleaning tips on my Blog About Cleaning Foraged Fungi.
• Be aware that "partially turned" specimens do exist. While the host mushroom is not toxic, small sections of "unturned" Russula that exist on a lobster mushroom are prone to rapid decay and general unpleasantness. If the majority of the mushroom has all the features of a lobster, this section can be cut away. (see photo)

The parasite failed to completely fuse over the gills of the host Russula, which turn brown and decay quickly compared to the flesh of the rest of the lobster mushroom.

Lobster Mushrooms For Use as a Natural Dye:

Natural color obtained using my lobster mushrooms, by Marion Richards.

• Older, darker specimens are known to produce a stronger dye.
• Natural wool and unbleached/unaltered fabrics are best for picking up color.
• It is the colored, outer section of Hypomyces that provides the color for dye.
• This outer section can be peeled if desired, and the rest of the mushroom can be eaten if of sufficient quality.
• Since the parasite can regrow color on exposed surface area, more potential dye color can be coaxed from lobster mushrooms by slicing/chopping them and leaving them alone for a couple days. (see pic)
• Here is an excellent Youtube Video by Margaret Byrd about dyeing with lobster mushrooms. It is very detailed, providing more sheer information from an obvious expert on the subject than I have seen elsewhere.
  
• The general process for dyeing is to boil your desired material with lobster mushrooms at a 1:1 ratio for 1 hour.
• Given the foul, dead fish odor of old lobster mushrooms, boiling outside is recommended.
• Changing the PH will change the color obtained, and a variety of mordants can be added to help affix the color.
• If you're interested in purchasing lobster mushrooms for dye, I happen to sell those here. 🙂

The orange color on the interior of this stem was obtained after slicing the stem and leaving it to sit for 36 hours. This extra orange will help create a stronger color in the dyed material.

Lobster Mushrooms: How and Where to Find Them

Lobster mushrooms can be surprisingly tricky at times, especially here in the Pacific Northwest where they often prefer to hide under the duff layer for the majority of their (or entire) lives! While some of them pop out and scream "come pick me" from all the way across the forest with their bright orange coloration, the most of them stay hidden beneath a layer of moss and needles. These hidden beauties sometimes never expose their color to the world, the only sign that they exist being a "shrump" (mushroom lump) giving away the location where they're pressing up on the duff from underneath.

• Lobster mushrooms are a summer/early fall mushroom here in the PNW, with the heaviest fruiting from roughly July to October.
• Many lobster mushroom areas will fruit with no rain at all, due to inherent moisture/fog layers. Running creeks will often produce lobster mushrooms on either side, early in the season.
• Check iNaturalist observations for Hypomyces lactifluorum to see where (and WHEN) they fruit in your area.
• The heavy spore print of lobster mushrooms will often expose their locations with a white patch of needles/duff next to their shrump.
• That shrump (raised patch of duff) is sometime the only way to locate these mushrooms. If you see an exposed one, look around nearby for bumps in the ground and see if there's a lobster underneath.
• Lobster mushrooms only occur in North America, growing widespread on the eastern half of the USA and concentrating along the west coast, as well as the southern parts of Mexico. (see map)

Map of lobster mushroom observations, courtesy iNaturalist.

• Lobster Mushrooms grow in the majority of locations that R. brevipes grow in North America. Finding R. brevipes is certainly not a guarantee that H. lactifluorum is present, but it's possible and even likely depending on your location.
• R. brevipes associates with a wide variety of trees including douglas-fir, hemlock and spruce.
• Second-growth forests often seem to be the ideal habitat for lobster mushrooms to thrive in great numbers.

Lobster Mushrooms: The Host/Parasite Relationship

A fascinating "half-turned" Lobster Mushroom specimen, where the parasite failed to infect roughly half of the host Russula, leaving both the gills and flesh of the host. In theory, half of this mushroom should produce Russula spores, and the other half would make the spores of the parasite.

The host/parasite relationship between the ascomycete sac fungi (Hypomyces lactifluorum) and its gilled host in Russulaceae is complicated to say the least, and still being studied to determine exactly when it takes place, and how it happens.

Heck, even *what mushrooms the parasite can attack* is a matter of some contention. It is generally accepted that H. lactifluorum is very specific about its hosts, only attacking non-toxic members of Russulaceae. (The most commonly suggested species for hosts besides Russula brevipes are Lactifluus/Lactarius, such as Lactarius piperatus)

When it comes to proof of hosts outside of R. brevipes itself, however, I have been unable to find any. All DNA testing that I can locate to date, *and all civilian efforts to prove hosts beyond R. brevipes* result in showing H. lactifluorom infecting R. brevipes without fail.

Compound this lack of DNA evidence with a lack of physical specimens (I have many photos of half-turned Russula that I have personally found, yet have never seen a single half-turned Lactarius on any forum or website over many years of searching), and the doubt really starts to pile up. I will happily change my mind and edit this blog if anyone can show where the theory of Lactarius/Lactifluus hosts came from, or simply proof that it happens.

For our intents and purposes: The parasitic fungi Hypomyces lactifluorum infects the host mushroom Russula brevipes.

It does so under the ground, the mycelium of the parasite attacking the mycelium of the host, resulting in the fruiting bodies appearing as "lobsters", with the gills of the host fused over and the color usually changed to orange. Most lobsters emerge fully turned, and continue to grow and deepen in color *as lobster mushrooms*, they do not turn into lobsters from already grown Russula. As this is also a matter of some contention, here is visual proof of that:

Left: Original photo of young lobster mushroom. Right: 5 days of growth.

While there may be *some* small amount of turning/color (as evidenced by the regrowth of color on exposed surface area) after a Russula grows if the parasite is present, do not expect any full grown Russula to somehow turn into a lobster mushroom.

Even fully "turned" lobster mushrooms still contain some DNA from their original host Russula throughout their entire fruiting body, more concentrated toward the center of the stem. I will also occasionally find sections of watery, weak flesh in the interior of Lobster Mushroom stems that I assume are bits of the original host that failed to "turn". The gills of the original host are also sometimes visible when a cross-section is performed.

The gills of the host Russula are still visible in a cross-section of this lobster mushroom.

There are also over 50 different species of other Hypomyces that attack a wide variety of hosts, such as H. chrysospermus (the Bolete-Eater), which attacks species in Boletaceae, and H. hyalinus on Amanita. While a very few of these species of parasite might be eaten by the brave, calling any other species of Hypomyces a "lobster" is pretty misleading, in my eyes. Lobster mushrooms get their name from their bright orange coloration and seafood-like taste. Terms like "green lobster" for H. luteovirens cause some confusion among beginners, who might assume that it just a variation of lobster mushroom that shares the same edibility.

Also of note is that the parasite will sometimes just leave one or two Russula alone, even when the surrounding area is thick with pure Lobster Mushrooms. Is this the Russula somehow resisting the effect of the parasite, or does the parasite intentionally allow the growth of a certain number of Russula to ensure that their host continues to propagate? Perhaps someday down the road when more studies have been done on the relationship between these two fungi, we'll know for sure. 🙂

One of the author's "Lobster Mushroom Gradient" layouts, showing the different shades that the mushroom can be.

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I Will Dye For You Lobster Mushroom Sticker