Posts tagged Laccaria proxima

Laccaria proxima – an abundant species

Laccaria proxima is known from both Europe and North America.   In my area it is strictly associated with pine plantations.   I believe that the pine species is the Maritime Pine, Pinus pinaster.  The occurrence of L. proxima is variable, but it appears to be extremely common in well established plantations with trees of a diameter of around 300 mm.

In June in these forests there is a wide variety of fungi, including several small mushrooms with brown caps.   Laccaria proxima is distinctive in that it has pale salmon pink gills that are not crowded.  This distinguishes it from another abundant species with yellow gills that are crowded as shown below.  Laccaria proxima has a white spore print.  This should be checked.

Laccaria proxima, with pink gills on the right.

L. proxima varies in size from about 20 mm to 80mm in diameter.  The stems can be up to 100mm long and they emerge from the pine needle mat. Underneath the mat, one can see the white mycelium in a layer on the top of the soil.  As the mushrooms grow, they move from having slightly inrolled margins to curling up so that the gills are exposed.   Below are pictures of the different stages.

A young specimen

Mature specimens

A distinctive feature is the striations on the stem.  These stems are quite tough.  A small white mite was present on the specimens  that I picked in late June.   They are a long lasting mushroom that does not suffer gross attack by insects or slugs.   In the sandy soils of WA pine plantations, these mushrooms are sometimes contaminated by sand that splashes up as a result of falling raindrops.

I prepared some of these by washing them and then frying in a pan with oil.   I had to decant some of the water during cooking as it had caught up in the gills.  I added some ham to the mixture in the pan and ate them on toast.   The taste resembled Volvariella slightly, though it was not as intense.   I found that it left a pleasant after-taste when I had finished the meal and this lingered for some time.

There is a smaller abundant  native species, Laccaria lateritia.  It is very similar in general appearance, but it is smaller and the stems do not display the same striations as in L. proxima.  It is probably edible as well but I have not tried it at this stage.  It is interesting that various early documents refer to a red, juicy mushroom being eaten by indigenous people.   Laccaria lateritia is possible candidate for this, given it’s abundance, as is some species of Hygrocybe, though they are less abundant these days. There is insufficient information to be able to identify the mushroom in question.

This is an interesting mushroom because of its abundance and well established edibility from overseas experience.  Though it is not considered to be a choice edible, it is quite palatable and the pleasant after taste makes it interesting.  I suspect that it has a flavour-enhancing quality to it.

11 January 2021

Recent chemical analyses have revealed the presence of a couple of unique alkaloids in this species. These are called proxamidines and the molecules contain and 8-membered ring that includes two nitrogen atoms. One of these is shown in the figure below. The two blue nitrogen atoms can be seen in the structure. The compounds were tested for biological activity but the only thing that was found was a weak herbicidal effect on a cress specimen using a standard technique. It has been suggested that these alkaloids may be responsible for the lack of insect attack that I mentioned above.

Proxamidine

There are another couple of interesting features of Laccaria. The genome of Laccaria bicolor was published in 2007 at which time it was the largest fungal genome yet published at 65 megabases. In an article in Nature, some features of this rather large genome are discussed. One feature that is noted is the coding of multiple genes that give it the ability to utilise nitrogen sources, particularly ammonia. I have read this somewhere else where it was compared with Hebeloma aminophilum in this regard. I have actually tried to test this out by spreading some urea on a patch of pine duff but the only thing that was apparent was a greater than normal amount of Amanita muscaria in that patch.

Yet another feature of Laccaria is that it has been found to be stimulated by electrical impulses so as to produce a greater number of fruiting bodies. This has been found both in field tests and in nursery pots. Many other mushrooms respond to the same treatment, notably Shiitake.

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