Notes: Yellowish or cream-tinted Amanita. Can’t key this out in Aurora. Small size, about 2 inches across the cap, with white veil remnants; stipe with collar volva (I have a better photo, but on a different floppy); stipe is white with white annulus; however, the stipe does stain light yellowish when cut, about half-way up; gills white. Growing in nearly pure Western hemlock stand.
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My understanding of mushroom species requires cultivation to be accurate. Since most fungi have not been cultivated to date, the concept of species remains somewhat in flux. For example, Dr. Eric Danell several years ago realized after accessing the original collection of Cantharellus formosus Fries that the DNA from this fungus is not what Dr. Alexander Smith considered to be C. cibarius throughout the northern hemisphere. It also impacts the total number of known or suspected species currently in existence. Many mycorrhizal species, i.e. Tuber gibbosum, are now known to mycorrhizal with only a single host species. Douglas fir is known to support mycorrhizae of at least 2500 different mycorrhizal species, many of which are known from spores, but whose sporocarps have yet to be found.
One of the fascinating things about mycology, IMHO.
Have dried this collection, and am getting ready to send to Dr. Tulloss.
Hybridization is a real obstacle to any universal species concept. The frequently cited examples of horses and donkeys producing infertile mules is a bit misleading. Mules and hinnys can sometimes produce viable offspring when back crossed with a full-blooded horse or donkey.
“Female mules have been known to produce offspring when mated to a purebred horse or donkey, though this is extremely uncommon. Since 1527 there have been more than sixty documented cases of foals born to female mules around the world. In contrast, according to the ADMS, there is only one known case of a female hinny doing so, and she produced a mix which has, thus far, only been documented once among the offspring of female mules…”
Backcrossing inter-specific hybrids allows for genes to move from one species pool into another. Imagine a werewolf and a vampire mate and have a baby ( thanks to Lindsy for this example). The baby has all the special powers and weaknesses of the werewolf, but it can also morph into a bat like a vampire. The ability to turn into a bat and fly away whenever he is cornered by pitchfork wielding mobs of angry villagers gives the wolf-vamp hybrid greater fitness. Being otherwise just like a werewolf, the hybrid mates with a female werewolf and passes on his genes. Over not too many generations, the genes which code for bat transformation become integrated into the werewolf gene pool.
The process just characterized is called introgressive hybridization. Plant developers utilize it to isolate desired traits from one kind of plant and combine them with desirable characteristics of another kind of plant. The commercial hybrids between three natural species of Cannabis illustrate the effectiveness of this technique. Introgressive hybridization blurs distinctions between species based on offspring fertility criteria, because sometimes interspecific hybrids are fertile.
Ring species also cause problems for interbreeding species concepts.
A ring species is composed of a number of populations of very similar organisms that are usually dispersed along a geographic boundary like a coastline or mountain range. Populations at one end of the range are reproductively compatible with neighboring populations but not with populations further down the line. Individuals from population A in the south can breed with individuals from population B in the mid latitudes but not with population C in the north. Population C can also mate with B but not with A. Even though A and C cannot produce viable offspring, they still share a common gene pool through interbreeding compatibility with population B. A and C are the same species even though they cannot interbreed.
Analogous dynamics are in play with multiple mating types in fungi of the same species.
Also of note, not all hybrids are interspecific. Infraspecific hybrids are also common. Workman stabilized a hybrid between two different strains of Psilocybe cubensis .
Of course, if one holds firmly to the interbreeding species criterion, then interspecific hybrids are never possible; if the mating produces fertile offspring, then the two parents are by definition the same species. This however would entail the demotion of most plant species to varieties, a consequence that some find more illuminating than troubling.
We have visited this issue before, and I remain sceptical about “hybrids” forming between gemmatoid and pantherinoid taxa. This answer can probably be improved by others because I’m just sitting down and writing it out without reference to literature, etc.
The combination of morphological studies and molecular phylogeny has shown that some concepts of some taxa are too narrow (e.g., the rank of “variety” may have been over-used in Amanita muscaria). Some species concepts have been too broad (some so-called “varieties” of muscaria seem more likely to be properly treated as separate species). Not surprisingly, material from some isolated ecosystems that look a bit like a familiar species appear to be genetically distinct.
When evidence shows that white, yellow, orange, and red muscarias are not separated into genetic tree-branches by current phylogenetic techniques, the simplest solution is to say that the color is variable in A. muscaria. This is just like saying that Homo sapiens cannot to be meaningfully divided into taxa by eye pigment or that the flowers of Portulaca can be white, purple, red, yellow, pink, etc. In the cited cases we don’t talk of hybrids, we speak of the variability of members of a taxon.
Amanitas have yet to be grown successfully from paired single-spore isolates. In other words (and this is true for other mycorrhizal fungi), mating tests have not been possible for Amanita. Molecular phylogenetic methods and morphological methods ARE available to create hypotheses about “specieshood.”
When a group of specimens that are strongly morphologically similar except for (let’s say) cap color, cap color may or may not be relevant to the assignment of names (old and/or new) to individual specimens. We have large toolkit of morphological methods (e.g., characters to be examined) that can be deployed. We have a growing repertoire of parts of the genome that can be sampled and compared. We should resolve to deploy these tools in trial cases in which “hybridization” is hypothesized. It should be acknowledged that these tools come with some basic assumptions about their application. I am willing to bet that the “hybrid” hypothesis has a low likelihood of being accepted as the most likely hypothesis. One or more “more or less variable” taxon(a) that do NOT hybridize seems much more probable to be the output result because this could be the simplest model explaining the data.
If we look at hybrids of DISTINCT species, at least some of the examples that quickly come to mind, they are hybrids that can easily be identified because they are unable to reproduce (mule) or can only reproduce clonally (hybrid ferns, certain hybrid lizards, etc.) or (if we accept the nongenetic barrier component in species definition) they will not reproduce in nature (ligers and tions), etc. Genetic methods can be used to address some of these models (discovering through molecular means that clonal reproduction is the dominant method, for example).
Hence, we have the tools to discover a “most likely hypothesis.” I doubt it will be hybridization.
An overheard conversation with Dr. Norvell, Jan Lindgren and Judy Rogers some years ago suggested that gemmata and pantherina were interbreeding, forming bizarre crosses. Since I haven’t spent much time growing Amanitas I don’t have an opinion on this. But several mycologists here in the PNW are of the opinion that the genus is truly more in flux than many would like it to be.
It seems to me that the margin of the cap is striate; the short gills appear to be squarely cut-off on their “stipe end”; the volva at the stipe base and attached to the bulb is ocreate/limbate. The volval remains on the cap seem submembranous, certainly not an evenly distributed powder or powdery warts. The species is clearly not a member of section Amidella. I think it is reasonable to say it is a species of sect. Amanita. The form of the volva suggests that the species is in the gemmata-group or, possibly, the pantherina group. As to names, this doesn’t appear to fit taxa that have been called gemmata or pantherina in the Pacific Coastal region. If it has a name, it might be one of the taxa Murrill described from the Pacific Northwest of the US in the early 20th Century: praegemmata, pantherinoides, or umbrinidisca. Jenkins thought that the first two names were synonyms and made them a variety of pantherina. This is still their current status. I don’t know anyone who feels they know these taxa well.
There’s a project for you.
Created: 2008-10-23 08:54:01 CEST (+0200)
Last modified: 2008-10-23 08:54:01 CEST (+0200)
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