Ahh, the wonderful world of mushrooms. Winter in California means the arrival of rain and therefore the arrival of mushrooms! Yahooo! I wanted to put together a small collection of recently observed mushrooms from the Mendocino and Sonoma County area. Since mushrooms come in almost every color I thought I’d organize them into a rainbow-like pattern with a little bit of info on each.

While plants in the winter are beginning their growing phase, fungi is in its prime! Party time! Now, remember, mushrooms are fungi, the fruiting body, the reproductive structure of the fungi living and thriving underground, in tree trunks or woody debris. Only until the right conditions come together is when signals are sent to the fungal mass underground to bear a fruit to the surface. Mushrooms really only exist to provide the structure to produce and disperse the fungi’s spores rapidly. This is why when conditions are right- up mushrooms appear to come out of nowhere, but they often decay and dissolve away pretty rapidly, as their work is done.

Why so colorful?

But why be so colorful? At least to our human eyeballs? Why be purple when the surrounding habitat is mainly brown and green? Why when chomped on by a deer or rodent turn colors like blue or orange?! This question is what I wanted to explore. But like other naturalist questions it remains mostly unanswered.

What we know so far:

• Brightly colored mushrooms can be a warning sign of toxicity, like other brightly colored critters. But for mushrooms it really only matters that the structure is not consumed before the spores are formed.
  • Once the mushy has reached maturity perhaps consumption is preferred! If even knocked over, taken to another location or eaten, the spores have a potential to be dispersed further from the parent fungi.
• But bright coloration might actually attract dispersers, helping the fungi spread its spores!
  • Mushroom hunters will actively chuck mushrooms to help spread their spores. It’s hard to avoid the bright colors as humans, so a win-win for human and fungi!
• Other shapes, smells and textures attract insect disperers, which may correlate to color; I’m not sure.
  • Certain mushrooms attract insects which visit the mushroom and unknowingly act as a spore transportation device. An example is stinkhorns and flies.

• But another angle to the coloration question is climate change. Huh? Researchers at the Technical University of Munich suggest that dark colored fungi use the ability to absorb the heat from the sun to enhance reproduction.
  • Similar to how animals, especially cold-blooded animals function differently at cold versus warm ambient temperatures, being darker colored means heat can be absorbed faster. This is well documented in colder climates. Makes sense right?
  • Well this was also observed in mushrooms. Krah et al in 2019 found ” mushroom assemblages are significantly darker in areas with cold climates.”
  • Perhaps this ability to capture heat more quickly than light colored mushrooms in cold environments have a reproductive advantage, a potential overall fitness advantage. But this idea needs to be more fleshed out. Hehe, flesh, like mushroom flesh. . .
  • BUT with the changing climate perhaps we will see a shifting of mushrooms colors in colder environments, or the opposite in warmer environments? Interesting stuff!

But before we get too depressed by the state of our one and only earth, let’s look at some bright and cheery mushrooms! All photos were taken by myself or by my also mushy obsessed partner.

Selection of Colorful MUSHROOMS:

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Rubroboletus pulcherrimus, Red Pored Bolete

After every mushroom hunt, on the ride home we tell each other our top three mushrooms. Usually we have differences in two out of three, and have one that we both loved, and this chonker was one of those shared favorites. 

Bushwacking around the Sonoma/Mendocino coast can be quite enjoyable. No poison oak, for one thing. Another big plus is the large network of mini trails stomped out by fellow mushroom enthusiasts. But to find areas with no overturned mushrooms that means going beyond those cute little trails and batling small creek ravines, spider web facials, and fighting evergreen huckleberry. BUT there are rewards! And this beautiful big red boy is one of them. 

Mr. Deer took some big bites out of the cap showing the beautiful blue staining, but leave the munching to the critters as this bolete is toxic to humans. The blue color is caused by an acid compound in the flesh becoming exposed to oxygen. Slicing through the cap breaks the cell walls which oxidizes an acid inside, converting it to a quinone compound, which is the blue color we see above. I’m no chemist, but other boletes are better understood when it comes to the specific chemical compounds causing the staining. For this R. pulcherrimus, it remains a mystery, as far as I can tell.

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Lactarius deliciosus, Saffron Milkcap

Many members of the Genus Lactarius have beautiful orange, sherbert, and peachy colored flesh, (so yum) but this Saffron Milkcap in particular has been particularly orange this winter. 

The Lactarius deliciosus group, is a real eye catcher when young and fresh but as it ages, it takes on an ickier appearance as it gains greens and browns throughout. 

As a Lactarius, it exudes a liquid-like substance known as latex when young gills are sliced. The color is a key identifying feature, appearing bright orange, like a sickly orange halloween candy you try to trade with your younger sister for some lemon heads. 

Some Lactarius group members have latex that changes color, which is super cool to watch! Some latex bleed white but change to yellow, but this one stays generally orange but discolors the surrounding tissue to red and eventually green. I haven’t observed this, but I’ve put it on the to do list for next weekend. 

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Cortinarius viridirubescens, Yellow-Green Cort

Just look at that almost neon, chartreuse yellow-green coloration, wow! Even though it has no special odor or taste, the highlighter-esc color on the cap and stipe makes this mushroom quite distinct. While we found it under Tanoak, but it is usually found under Coast Live Oak. 

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Genus Russula, Brittlegill

Kind of tricky to find a good green mushy to highlight here. Many mushrooms as they age turn a weird grey-green color, but very few are freshly green. Well there certainly is a lot of green in the forests of Northern California as it is! But this Brittlegill does have a nice light olive green cap. The Russula Genus can be a tricky one to ID down to species, and with over 100 species known to be in California, you can’t play guessing games here. But in general the group is characterized by no latex, colorful caps (can be pink/red/purple), white stipes that snap like chalk, and brittle gills. Three additional steps required to make a solid identification include, noting spore color/make a spore print, taste, and what trees are growing in the area. A great by-product of mushroom identification is forcing you to learn your trees. While most naturalists may know how to identify most trees at ease, I think mushroom-ing makes you recognize when forest composition changes, and identify trees much faster, often by only looking at bark or fallen leaves.

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Leptonia carnea

Ah one of my most favorite mushies off all time! When the Mr. and I first got into mushroom hunting we spent long days all over the Santa Cruz Mountains, located in the Bay Area. After a very wet day, and just about ready to head back to the car we tried one last location. We bushwacked down to a small stream, which Trevor trekked across to survey the other side and I stayed. When scanning a patch of beautifully green moss adjacent to the stream bank I was shocked to see this small blue blob just perched amongst the moss, in solitude. I let Trevor finish his survey of the other side and stood nearby this beauty and let his eyes find it himself. Oh boy, it made the whole day worth it! What the dickens had I just found?! A Leptonia carnea! We of course didn’t know what it was at first, and later got identification help through the iNaturalist community. 

Distinctive features of L. carnea include the gorgeous indigo-blue cap separated by the white, pale  beige or light blue/gray gills, and the same strikingly blue colored stipe.  But Leptonias in general are generally small mushies with pink spores and are typically some dark shade of blue, purple or grey. Unfortunately, like many other fungi Genera, additional analysis is need to truly identify down to species. Mushroom identification can be rewarding one minute and frustrating the next. The hobby is a good lesson in accepting the unknown.

If you were curious if this blue babe was edible, or how it tastes, the answer to both is farinaceous; which means like starch. Eww. 

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Laccaria amethysteo-occidentalis, Western Amethyst Laccaria, or Laccaria A-O

You can find this common laccaria poking through the duff of conifers and hardwoods. But the purpley-grey to purpley-brown is anything but common. While other mushrooms like Russulas have purple coloration I really like this one because both the cap and stipe are similar purple tones. Even the basal mycelium is purple-ish! But the true star features are the brighter purple gills which retain their color as the rest of the mushroom ages into greyer shades of purple. 

Laccaria A-O are edible, but only in clean environments, these puppies uptake and store heavy metals in the flesh. Thank you for this ecosystem service! 

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Cortinarius seidliae & Cortinarious vanduzerensus , Slimy Purple-Stemmed Cort

Uhh, freakin fabulous! This slimy colorful mushy is a trail stopper. One you have to stop on whatever trail you’re on and marvel at. The cap. Those dark chestnut-y brown spreads its striations towards the lighter colored edge all underneath a thick layer of glutinous slime. The stipe. Lilac to light lavender tones are quite striking against the conifer duff. Eventually the stipe melts away to a white base color. Stunning!

I have two Cortinarius mushrooms listed above. C. seidliae was recently described, previously known as C. vanduzerensus, but this group may have more undescribed species.

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Shaggy Mane, Coprinus comatus

When young this mushroom is like a giant long oval egg with lots of shaggy scales. But as it becomes a classic mushroom shape, the cap liquifies into a black inky substance as the margin curls inward.

These edible pups and the Genus Coprinoid can be found in many environments, pastures to forests to grasslands, lawns, and even growing on poop. The Greek word kopros means “dung.”

In Summary:

It’s easy to appreciate the colorful world of mushrooms from afar, but you’ll get a much better experience by getting up close and personal. As personal as fondling, caressing, kissing, eating, carefully slicing, and eventually propping them up nicely for a fellow mushroomer to fawn over. Go give it a try!

In case you are wondering what to look for when out in the woods, these are the things we look for/take note of when observing a mushroom:

• Take a picture of:
  • Cap (Top of the mushroom)
  • Stipe (Stem)
  • Gills (or pores)
  • Slice it in half top to bottom to see the inner tissue (context)
• Take a note of:
  • Cap Width
  • Stipe Length
  • Stipe Width
  • Smell 
  • Staining of stipe, cap, gills, context tissue when handled or cut
  • Taste of tissue, cap slime

Happy Mushrooming!

• Resources
  • Mushrooms of the Redwood Coast by Noah Siegel and Christian Schwarz, 2016
  • California Mushrooms: The Comprehensive Identification Guide by Dennis E. Desjardin
  • Why do mushrooms come in so many shapes and colors? on BayNature by Dr. Dennis E. Desjardin
  • Krah, FS., Büntgen, U., Schaefer, H. et al. European mushroom assemblages are darker in cold climates. Nat Commun 10, 2890 (2019). https://doi.org/10.1038/s41467-019-10767-z
  • Why some mushrooms are darker than others, Franz-Sebastian Krah on Nature Research Ecology & Evolution Community by Nature.com
  • Genus Leptonia from Santa Cruz Mycoflora Project
  • The secret of Mushroom Colors on Phys.org
  • Bluing Components and Other Pigments of Boletes by Stephen F. Nelsen
  • Tom Volk’s Fungus of the Month for July 2003, Gyroporus cyanescens