Observation 21010: Morchella importuna M.Kuo, O’Donnell & T.J.Volk

When: 2009-03-26

Collection location: Paradise, Butte Co., California, USA [Click for map]

Who: Shane Marsh (Mushane)

No specimen available

Proposed Names

20% (4)
Recognized by sight
-8% (3)
Recognized by sight
62% (3)
Used references: vertically-oriented ladder-like pits, dark color, widely conical to ovoid, ridges eroded in age, wood chip habitat on West Coast. Kuo et al., 2012, Taxonomic revision of true morels (Morchella) in Canada and the United States

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Don’t know…
By: Douglas Smith (douglas)
2012-04-13 23:28:33 CST (+0800)

Kinda sounds like to make it things work well, you can just interpret into any range you want, and then it all starts to loose meaning for me… I’ll re-read what they mean by laddered, and see how that goes. But it doesn’t say vertically-oriented, it says the puts are vertically elongated. Which I would interpret as the pits are taller than they are wide. Which is not tru here, or in his photo in the paper. Or maybe he meant when it was laying down?

If I am able to interpret color as much as you are saying here, I think then we have to completely ignore all colors there, and perhaps “yellow” and “black” morels are meaningless? Is that what the paper is saying?

Still confused on how to use this to id morels yet I guess.

shape of pits
By: BlueCanoe
2012-04-13 07:58:20 CST (+0800)

In M. importuna, the key is that the horizontal ridges are sunken relative to the vertical ridges. This makes the so-called “ladder” appearance, which I think is what they are calling vertically-oriented in the species description. The individual pits, as shown in their own photograph, may be wider than tall.

With the color, I would try to be flexible in the interpretation. There’s a reason they give a range of colors for most of these new species. M. importuna are really gray when they’re young, see image 112759 or image 211766. When they mature they have grayish brown to brownish yellow pits, and dark grayish brown to nearly black ridges. Sounds morel-colored, to me. :)

Seems too…
By: Douglas Smith (douglas)
2012-04-13 07:42:51 CST (+0800)

These seem too yellow to be M. importuna? Pits should be grey, dark grey, brown. Although then he finishes it off with brownish yellow at maturity, not sure what color that is? And his photo for M. importuna has rather yellow-tan pits if you ask me… I seem to be getting more confused as I try to read this thing, and compare to photos… Also he says the pits are vertically elongated in all stages, but here they are rather short vertically. But also in his photo for the species, the pits are rather short vertically… Starting to feel like I am drunk stumbling along…

from Kuo et al. 2012
By: Danny Newman (myxomop)
2012-04-13 06:26:03 CST (+0800)

Morchella rufobrunnea is easily distinguished on the basis of “its abruptly
conical young cap with pale ridges and nearly black pits, and its rufescence” (Kuo 2008). It appears in woodchips and landscaping settings on the West Coast from California to Seattle.

(emphasis added)

these ridges & pits have the reverse pigmentation, a tentative match for M. importuna

By: Johannes Harnisch (Johann Harnisch)
2009-05-18 22:41:12 CST (+0800)
Mycorrhizal fungi form a symbiotic or mutually beneficial relationship with 80-90% or more of all plants and trees that have a root system; there is about 5,000 mycorrhizal fungi. The mycelium forms a sheath around the rootlets with some hyphae penetrating the roots and can actually live within the rootlets. This complex association of fungi and plants is called mycorrhiza (my’kuh rye’zuh). The rootlets provide the fungus with moisture and organic compounds such as carbohydrates and the fungus by digestion of organic matter in the soil make nitrogen, sugars, phosphorus and other minerals such as copper and zinc, available to be easily absorbed by the plant or tree.

This relationship with the rootlets is said to provide added resistance to diseases, also helping trees to survive in poor or exposed soil.
Fungi have proved invaluable in reforestation projects and it is estimated that the mycelium content of topsoil within a typical Douglas fir forest in the Pacific Northwest may be over 10% of the total biomass.
It has been found that Mycorrhizal fungi do not survive very well without their being connected to their host, studies have also been shown that when pine trees are introduced to a new area they do poorly until supplied with the appropriate mycorrhizal fungi,
One tree may have many mycorrhizal associates such as the isolated Douglas-fir described by Alexander Smith, which had over 50 mycorrhizal fungi growing under it but some may have as many as 2,000 each doing its own part.
How mycorrhizal fungi know how to store up excess nutrients, and release them when their host is in need, is still unknown?

Definition of mycorrhiza
By: Irene Andersson (irenea)
2009-05-18 15:15:29 CST (+0800)

is “modified roots consisting of a mutually beneficial relationship between plant roots and fungi”. If the tree gains something from the morel, it’s mycorrhiza. Is there any evidence that it does? If not, the morel that invades tree roots is an ectoparasite.

Morels CAN be mycorrhizal
By: Michael Wood (mykoweb)
2009-05-18 00:55:15 CST (+0800)

Tom Volk presented the work of one of his grad students, Marsha Harbin, at a meeting of the MSSF several years ago. The study showed that the species of morel they were working with could form mycorrhizae with elms in the lab.

I have seen several papers showing Morchella can be mycorrhizal, a quick search turned up these:

The association of Morchella rotunda with the roots of Piceas abies

Mycorrhiza-like interaction by Morchella with species of the Pinaceae

Here’s the abstract of the latter:

Isolates from two species of Morchella were
tested for ability to form mycorrhizae in pure culture
synthesis with Arbutus menziesii, Larix occidentalis,
Pinus contorta, Pinus ponderosa, andPseudotsuga menziesii.
Ectomycorrhizal structures (mantle and Hartig
net) formed with the four species of the Pinaceae but
not with A. menziesii. Results are compared to previous
studies on morel mycorrhizae and discussed in an ecological

A LOT more research needs to be done. Where, when, and how often Morchella forms mycorrhizae in nature is an open question…not to mention which species may be involved.

By: Dave in NE PA
2009-05-17 23:28:19 CST (+0800)

Kuo begins the previously mentioned discussion with comments from Buscot and Roux (1987) about the possibility that the association with tree roots may indicate parisitism. But Kuo claims further research has “determined that, rather than being parasitic, morels that form structures around tree roots are mycorrhizal.” Kuo then goes on the give a brief synoposis of the benefits derived by the tree and the fungus in this type of relationship. A color photo with caption “Cross sections of rootlets in mycorrhizal partnership with morels” is found on page 144.

I have been searching
By: Irene Andersson (irenea)
2009-05-17 16:20:25 CST (+0800)

and searching, and searching, for evidence that Morchella species create mycorrhiza, but not found any.

What is called ectomycorrhiza-like hyphae around tree roots, does not necessarily mean benefits for both the mushroom and the tree. Using the term mycorrhiza in a broader sense than a definition that means it’s symbiotic, makes it rather useless, since most mushrooms send their hyphae anywhere there’s nutrition to gain, and occasionally become “mycorrhizal”. If the term is used in a wide sense – morels are very likely mycorrhizal with strawberries too.

This kind of ectomycorrhiza can just as well mean that these morels are (more or less successful) parasites on living/weakened tree roots, or taking advantage of nutrition that’s created there – by bacteria and/or truly mycorrhizal fungi.
A possible result is also weakening of the trees, and morels are biding the time to get dead roots to feed on.

Prolific fruiting
By: Paul Derbyshire (Twizzler)
2009-05-17 02:37:48 CST (+0800)

after the tree dies might be a way for some mycorrhizal fungi to abandon the sinking ship though.

By: Dave in NE PA
2009-05-16 22:54:13 CST (+0800)

Kuo references a study by Harbin and Volk in which a mycorrhizal morel+elm relationship was observed in a lab. Kuo’s assertion that morels might also be saprobic is based upon studies in which morels have been cultivated in treeless laboratory environments.

My own experience with orchard morels is that during some good years a few come out around healthy-looking apple trees. When the tree dies, larger numbers of larger morels fruit nearby the same tree; even if morel friendly weather conditions are marginal. To me this suggests that the morchella organism has been coexisting with the live apple tree. When the tree dies, the fungus then taps whatever nutrition is available in the dying roots. Orchard morels in my area do not spread to nearby morel friendly environments. One orchard I hunt is full of White Ash and Yellow Poplar, but morels appear only by the apple trees. When a tree has been dead for 4 years and there are no other apple trees nearby, no more morels appear in that area.

By: Erin Page Blanchard (CureCat)
2009-05-16 17:22:12 CST (+0800)

More likely that the Morchella species you are finding no where near trees are not mycorrhizal, instead they are probably saprobic.

But then again, finding Morchella mycorrhizal with Madrone trees this year was quite the surprise!

Finding mushrooms under a tree
By: Irene Andersson (irenea)
2009-05-16 16:00:15 CST (+0800)

doesn’t necessarily mean they are mycorrhizal. They can find a suitable environment there, taking advantage of the shadow, nourishment from leaves and debris or injured roots. The best sites for morels (Morchella species) I have seen, have been abandoned industry areas with torn down buildings and mouldering concrete. Not a tree in sight, but often among wild strawberries. Maybe they are mycorrhizal with strawberries?

By: Erin Page Blanchard (CureCat)
2009-05-16 14:23:35 CST (+0800)

Anecdotal accounts are great for spurring further investigation, but cannot be quantified.

>For a discussion of the possibility that morels may be both
>mycorrhizal and saprobic

Thank you for the reference. I don’t have access to a copy of that book, so I can’t check out the excerpt.
I’m not really looking for discussion on the issue, I’m looking for studies. Last year I brought up the issue of the possibility that any mushrooms might be able to be mycorrhizal and/or saprobic at a reading group meeting at UCB. Everyone (including Tom Bruns and Else Vellinga) was adamant that there was NO scientific evidence to support that hypothesis- and not because it had not been studied. There have been a number of articles researching the mechanisms of both growth patterns and despite their efforts, the results (thus far) point to there not being any fungal organisms which have both mycorrhizal and saprobic potential.

By: Dave in NE PA
2009-05-16 12:09:36 CST (+0800)

For a discussion of the possibility that morels may be both mycorrhizal and saprobic see Kuo “Morels” pp. 143-146 “What Do Morels Do in Nature?”

The one and only ornamental woodchip morel that I have ever found here in NE PA was very similar to the “Classic Black Morel” type that I gather in the living harwood forest…. blackening ridges, no red staining, whitish stalk.

By: Shane Marsh (Mushane)
2009-05-16 08:51:03 CST (+0800)

well thats true for every woodchip specimen ive found cure, all stain red.

Thank you
By: Johannes Harnisch (Johann Harnisch)
2009-05-16 05:32:06 CST (+0800)

I guess buy the looks of this I may not be finding Morchella angusticeps

By: Erin Page Blanchard (CureCat)
2009-05-16 05:11:25 CST (+0800)

The idea that any species of Morchella can be mycorrhizal and/or saprotrophic is to the best of knowledge, purely anecdotal. I have found no evidence to substantiate any of the claims.
If anyone has any reliable source of information confirming the ability of these mushrooms to adapt their growth habits in such a way, please refer me!

Mycorrhizal refers to a mutualistic relationship between a fungi and a plant, in which the mycelium of the mushroom and the roots of the tree are connected and both organisms exchange nutrients that neither may be capable of attaining on their own. The relationship is necessary for the fungi to produce fruiting bodies.

Just because a mushroom grows under a plant doesn’t necessitate that the two are involved in a mutualistic relationship. The mushroom might be a parasite on the plant, attached to it and absorbing nutrients, but the plant does not benefit from the mushroom and the mushroom may kill the plant.
Or it could be a saprobic fungi that simply grew under the plant due to increased moisture, or shielding from wind, or any other reason.

This species here is M. rufobrunnea. You can tell because of the non-mycorrhizal growth, but more obvious is the red staining that every mushroom appears to exhibit. This is the only species that I know of which bruises this colour. The colour of the mushroom itself varies a lot, especially with age.
It is guessed that all of the cultivated morels are M. rufobrunnea.
Kuo has a pretty good page for this species:

If you would like to understand more about the answers to many of the questions on this page, I suggest reading these two pages. Note that the answers are not straight forward nor simple.
Morel Data Collection Project
Classic Black Morel

By: Shane Marsh (Mushane)
2009-05-16 04:00:41 CST (+0800)

just like to add that most of the woodchip morels that I find are indeed at the base of landscaping plants such as rose or rhododendron etc, but a good percentage of them are just random all over the woodchips.

By: Johannes Harnisch (Johann Harnisch)
2009-05-16 03:10:11 CST (+0800)

Why sould Mycelium need to be scooped up with it?
Wouldn’t spores do the same….
The spores obviesly do not need to have a host to start to grow….
so why mycellium when it can be grown without a host.. or can it?/ …..

so how can you explain
By: Gerhard Koller (Gerhard)
2009-05-16 03:03:46 CST (+0800)

that morels grow with haw thorn, sloe and other rose plants on the one side and with ash and elms on the other side? Isn’t that mycorrhizal when you find them just beneath them plants, at least in Europe?

morchella elata
By: Dave W (Dave W)
2009-05-15 05:02:38 CST (+0800)

In PA I have found what I refer to as M. elata in both living hardwood forests and (only one time) on wood chips alongside a building in an urban area. To my knowledge, at least some species of morchella are believed to exhibit both mycorrhizal and saprobic tendencies. One possibility is that newly produced wood chips may include pieces of mycellium that get scooped up along with tree roots. Also, it is my understanding that the North American version of M. elata (probably DNA distinct form European ones) occurs with variable macroscopic traits.

By: Johannes Harnisch (Johann Harnisch)
2009-05-15 04:58:11 CST (+0800)

Then it isn’t
LOL I should know that…..being I read Paul stamets book on how to grow tham
and I guess the black ones I find in the woods up there are M. angusticeps
BTW is that one mycorrhizal?

By: Irene Andersson (irenea)
2009-05-15 04:42:05 CST (+0800)

The one I know as Morchella elata isn’t mycorrhizal – at least not with trees.

Must be…
By: Johannes Harnisch (Johann Harnisch)
2009-05-15 04:38:21 CST (+0800)

M. elata grows with trees and is mycorrhizal i think
so this can’t be it right?

Woodmulch morels
By: walt sturgeon (Mycowalt)
2009-05-15 04:33:15 CST (+0800)

I have found this species many years ago in wood mulched flowerbeds in NE Ohio. If anyone can identify it I would be very pleased!

By: Shane Marsh (Mushane)
2009-05-15 04:06:53 CST (+0800)

to my understanding, most of the woodchip morels in california are Morchella rufobrunnea
I’m still not sure what im finding though, probably definitely mixed collections.
it is a bit strange though, half greys half browns and a few blacks, but all growing in the same cluster?

Created: 2009-05-14 15:20:22 CST (+0800)
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