Danny’s DNA Discoveries – Laccaria and Hydnangium of the PNW
Introduction - click to expand
Laccaria have white spores (they lost their spore pigment and are actually inside the brown spored sub-order Agaricineae). They have somewhat waxy-looking, well spaced gills that make you think of the waxy caps. The caps are dry, somewhat hygrophanous and scaly which might make you think of Lepiota, but the gills are always attached. It's hard to describe, but you will soon be able to easily identify them by the fact that they are always orange or purple (or orange and purple) with tough, rough fibrous stems. They are also distinguished by spiny spores under the microscope. They are usually <5cm across, but some grow larger. All of the species that can possibly have purple tones appear to be related in a clade together. They are mycorrhizal, usually with conifers in the pine family and often with hardwoods like birch and willow as well.
abundant common uncommon rare - colour codes match my Pictorial Key and are my opinions and probably reflect my bias of living in W WA. Rare species may be locally common in certain places at certain times.
Trufflized species of Laccaria belong to the sister genus Hydnangium. So far they seem to merit their own genus, instead of the typical situation where the truffles are imbedded in with the non-trufflized species. They are recognized by pink folds and chambers inside. Our species has been called the EU name Hydnangium carneum, but Italian and California DNA differ by about 3% in the two sequences I've seen, so ours may be a sister species.
Hydnangium aff carneum © Jim Trappe
Summary of Interesting Results
Here are some of the newest, most interesting results of the study:
Species with purple - click to expand
The purple tones may be restricted to the mycelium at the base of the stem, and only when fresh.
Species mentioned: Laccaria amethysteo-occidentalis, nobilis, bicolor
Laccaria amethysteo-occidentalis - the most easily recognized species as it is quite large and entirely purple when young. Even after it fades to orange, the gills usually stay somewhat brightly coloured with a hint of lilac. It has an award winning number of syllables in its name (14) so it is often called "Laccaria a-o". It is a local species described from BC.
Laccaria amethysteo-occidentalis © Steve Trudell and Fred Rhoades
Laccaria nobilis - a somewhat large, scaly montane orange species that may have hints of purple when young. Described from Colorado. We have over a dozen recent local sequences. It is both larger and scalier on the cap and stem than Laccaria bicolor, described next. Laccaria proxima, below, is a lookalike without any hints of purple when young, but otherwise best distinguished microscopically.
Laccaria nobilis © Steve Ness
Laccaria bicolor - this more slender species is mostly orange but will have a hint of purple in the gills or in the basal mycelium at the base of the stem when young. It is not as large nor scaly as Laccaria nobilis. The gills are whitish and not bright when old. In this photo, the hints of purple have faded so you would need a scope to tell it apart from the species always without purple, below.
Mating studies showed that the EU biological species is also found in western North America (as they could mate with each other). However, the DNA seems to be somewhat variable as ITS can vary by 4 bp and 7 indels between the EU and here in the PNW, and by a few locations within the PNW, so there may be a clade of WNA sequences and clade of EU sequences. So far, we are assuming they are the same species.
Laccaria bicolor © NAMA and the Field Museum of Natural History
Laccaria spp. - three sequences (two uncultured from oak roots and one actual collection) from southern OR are unique species in the "purple" clade, but as they are only single sequences without any closely related sequences yet known, there's not much to say yet, except I'll be looking for more matching sequences.
Species without purple - click to expand
Species mentioned: Laccaria proxima, tortilis, laccata, montana, pumilla
Laccaria proxima - already mentioned above, is a robust, scaly EU species much like the sometimes slightly purple Laccaria nobilis, with DNA confirmed from BC, WA and OR.
probable Laccaria proxima © Fred Rhoades
Laccaria cf tortilis - a very small (<2.5 cm) species with a very pleated cap. We have reliable EU sequences of this EU species, but no local DNA to confirm that ours is the same species.
Laccaria cf tortilis © A and O Ceska
Laccaria laccata - average sized (<5 cm) species that is usually not as robust or scaly as Laccaria proxima. It can grow at low elevations, unlike the next two slightly smaller lookalikes. Until recently, every single orange species here was called by this name, and so were species with purple that had lost their purple tones. We don't have a type sequence of this famous EU species, but we have somewhat reliable sequences of it, and ITS DNA that matches well from BC and OR, so it is really here, just not nearly as common as everybody thought. I don't actually have any photos of a confirmed specimen - that tells you something about how abundant it was thought to be and how many other species there are. Mostly, I think Laccaria bicolor is mistaken for this.
Laccaria cf montana - fairly small (< 3 cm) species from high elevations. We still need reliable EU sequences to compare to to confirm that it does indeed occur here.
Laccaria pumilla - a small lookalike EU species also at high elevations. Best differentiated microscopically. 21 sequences from Skulow Lake, BC are within 5 bp in ITS and probably represent this species.
Laccaria cf montana © Andrew Parker and probable Laccaria pumila © Buck McAdoo
Laccaria spp. - we have 3 different genetic sequences from BC (two of them have been found more than once) and 1 in OR that can't be matched to anything yet. One of them could possibly be Laccaria montana, since I'm not sure what that sequence is. We clearly need further study of our local Laccarias.
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