Observation 49291: Humidicutis marginata var. olivacea group

When: 2010-07-20

Collection location: Seven Mile Lake Trail, Forest Co., Wisconsin, USA [Click for map]

Who: Steve Nelsen (sfnelsen)

No specimen available

Hygrocybe marginata. I think that this larger and umbonate one with darker stains is var.olivacea. The cap is 6 cm wide. There were also many of the smaller ones that I call var. marginata. The software “does not recognize” var. olivacea, which is found if you google it.

[admin – Sat Aug 14 02:05:53 +0000 2010]: Changed location name from ‘Seven Mile Lake Trail, Forest County, Wisconsin, USA’ to ‘Seven Mile Lake Trail, Forest Co., Wisconsin, USA



Proposed Names

36% (6)
Recognized by sight: you can argue name changes all you want… but this mushroom was never described as a Hygrocybe
oh, and with the new name you no longer need variates…

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Dan Molter (shroomydan)
2010-07-29 01:02:09 BST (+0100)

“Combines the presence of bright pigments with the absence of clamp connections”

If these two characters are consistently present in one kind and not the other, then a good case is made for inferring an evolutionary split.

thanks Noah, nice documentation (and nice hat, too!).
By: Debbie Viess (amanitarita)
2010-07-29 00:58:53 BST (+0100)

Altho I straddle the line between old school and new, indeed it would seem that this lovely mushroom is now being called Humidicutis marginata, and the species description is broad enough to include both of the former Hydrocybe/Hygrophorus varieties. If you look at Index Fungorum, sometimes a blessing and other-times a curse, you will see that indeed HyGROcybe marginalis has never existed (try typing it into the search engine, which will show the myco-taxo-history)…but HyDROcybe and Hygrophorus were indeed former names, now cruelly thrown aside in favor of Humidicutis marginata.

Change is inevitable, but we don’t have to LIKE it!!! And we are none of us always consistent in our new name useages, either, although that makes things a bit confusing as well.

Singer 1986
By: Noah Siegel (Noah)
2010-07-29 00:06:37 BST (+0100)

okay I have spent WAY to much time on this…
here are bits and pieces from Singer’s The Agaricales in Modern Taxonomy.

Type species: Hygrophorus marginatus Peck.

Characters: Those of the family.
Combines the presence of bright pigments with the absence of clamp connections; pileus mostly conical; lamellae neither deeply decurrent nor subfree; hymenophoral trama regular; pigment not easily dissolved in alkali solutions.
Limits: This genus differs from Hygrocybe in the characters of the hyphae, -
absence of clamp connections – and the type of pigment…

It differs from the other species without clamp connections, now distributed in two genera (Hygroaster and
Camarophyllus) in a combination of smooth spores, bright pigment, non-decurrent
lamellae, and regular hymenophoral trama…

Altogether, the differences are not striking, and only seemed to be more so to those who knew only the bright colored H. marginata from the North American woods, without taking into consideration much less pigmented but very closely related species such as H. czuica. Nevertheless, if duly separated generically from Hygrocybe as it should be, this group has more natural affinity with other hygrophoraceous genera than with the Tricholomataceae and has therefore been reinstated in the former
family. Humidicutis differs from Callistosporium in the relatively longer basidia, the lack of internal pigment bodies in spores, basidia and hyphae, and the habit….

By: Noah Siegel (Noah)
2010-07-28 23:39:36 BST (+0100)

here’s where Tricholoma subgenus Humidicutis was described http://www.cybertruffle.org.uk/...
And elevated to genus here with Humidicutis marginata as type

By: Noah Siegel (Noah)
2010-07-28 23:25:18 BST (+0100)

Murrill described it as Hydrocybe marginata not Hygrocybe in NA Flora, vol 9
“Hydrocybe marginata (Peck) Murrill.
Hygrophorus marginatus Peck, Ann. Rep. N. Y. State Mus. 28: 50. 1876.
Pileus fragile, often irregular or lobed, subcampanulate or expanded, often broadly
-umbonate, 2.5 cm. broad; surface glabrous, shining or minutely rimóse, golden-yellow, margin
thin, striatulate: lamellae emarginate, subdistant, broad, ventricose, yellow, darker with age,
orange or purplish on the edges : spores subellipsoid, 8 M long : stipe glabrous, pale-yellow, hollow,
often flexuous or irregular, 5 cm. long, 2-4 mm. thick.
TYPE LOCALITY: Northville, New York.
HABITAT: On the ground in woods.
DISTRIBUTION: New York and Massachusetts to Virginia and Ohio.
ILLUSTRATION: Hard, Mushrooms/. 173.”

and Redhead, Mycotaxon 83 2002
“In the analysis by Moncalvo et al. (2000, 2002),
there is weak bootstrap support linking the Chromosera-Hygrocybe
clade to the Chrysomphalina-Hygrophorus clade together with
Humidicutis (Singer) Singer, a third hygrophoroid genus. Bootstrap
analysis (but not MP analyses) support the phylogenetic placement of
Humidicutis marginata (Peck) Singer (type for that generic name) next
to the Chrysomphalina-Hygrophorus clade. These results potentially
bring into inferred evolutionary proximity, a group of taxa that form
muscaflavin based pigments (as surmised from other chemically
analyzed Hygrocybe) and other Hygrophorus, known to be able “to
induce extradiol cleavage of L-DOPA leading to the formation of
muscaflavin” (Gill & Steglich 1987, p. 86). Humidicutis is in part
defined by the absence of clamp connections and is otherwise different
because of pigment characters (see Singer 1986).

unless I’m missing something I am saying this mushroom was never described as a HyGrocybe

By: Robert Sasata (Sasata)
2010-07-28 22:44:50 BST (+0100)

I’m wondering if that’s just an error in the Redhead paper. Hydrocybe marginata (Peck) Murrill (note the d, not g) was originally named Hygrophorus marginatus Peck 1876.

Never named Hygrocybe?
By: Steve Nelsen (sfnelsen)
2010-07-28 22:26:36 BST (+0100)

Scott Redhead thinks that Murrill used the combination Hygrocybe marginata, (See Mycotaxon 83 2002, 19-57) and Noah Siegel (who be you) currently has a Hygrocybe marginata picture posted on M.O. (19601) taken in 2008. You can call it whatever you want, but I will continue to use Hygrocybe as the genus name. And what do you mean that you don’t have to use a variety name? All the ones I saw called Humidicutis marginata had no olive tones on the cap. If you don’t care what variety you have that is fine with me too.

Created: 2010-07-28 19:45:55 BST (+0100)
Last modified: 2018-08-07 19:42:44 BST (+0100)
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