Observation 215347: Panaeolus antillarum (Fr.) Dennis

Habitat: grassland, pasture, northwest inclined mountain slope; shallow, skeletal, colluvial, calcareous ground; open place, partly sunny place, exposed to direct rain; average precipitations ~ 3.000 mm/year, average temperature 7-9 deg C, elevation 610 m (2.000 feet), alpine phytogeographical region.

Substratum: rather old, washed-out horse dung.

Place: Lower Trenta valley, south outskirts of village Trenta, left bank of River Soča, east of farmhouse Maselc, East Julian Alps, Posočje, Slovenia EC.

Comments: Panaeolus semiovatus is considered as a mushroom with a ring on its stipe. However, some of them do not have it. In this observation there was no trace of it. Such observations are treated by different authors either on subspecies or variation level as Panaeolus semiovatus ssp./var. phalaenarum or on the species level as Panaeolus phalaenarum. Presently Index Fungorum recognizes as a valid name only Panaeolus semiovatus. How complex is the situation can be concluded by the fact that IF states 30 synonym names!

Growing in a group of four fruit bodies; the pilei diameters 52, 31, 14 and 13 mm, the largest pileus was 35 mm high; stipe firm, not hollow, without ring; stipe length/diameter 130/7 mm, 90/4.5 mm, 70/3 and 60/2.6 mm; SP dark warm brown, oac733 but darker.

Nikon D700/Nikkor Micro 105mm/f2.8

Proposed Names

19% (2)
Recognized by sight
Used references: (1) S. Buczacki, Collins Fungi Guide, Collins (2012), p 116.
(2) R. Phillips, Mushrooms, Macmillan (2006), p 261.
(3) D. Arora, Mushrooms Demystified, Ten Speed Press, Berkeley (1986), p 355.
(4) J. Breitenbach, F. Kraenzlin, Eds., Fungi of Switzerland, Vol.4. Verlag Mykologia (2000), p 261.
(5) G.J. Krieglsteiner (Hrsg.), Die Grosspilze Baden-Württembergs, Band 5., Ulmer (2010), p 597.
(6) M. Bon, Parey’s Buch der Pilze, Kosmos (2005), p 264.
Based on microscopic features: Spores smooth, somewhat flattened. Dimensions: 14 [15.6 ; 16.3] 18 × 8.8 [10.1 ; 10.6] 11.9 microns; Q = 1.4 [1.5 ; 1.6] 1.7; N = 30; C = 95%; Me = 16 × 10.4 microns; Qe = 1.5. Olympus CH20, NEA 100x/1.25, magnification 1.000 x, oil, in water. AmScope MA500 digital camera.
Based on chemical features: Smell slightly mushroomy; taste mild, indistinctive.
91% (2)
Recognized by sight
Used references: Gerhardt’s monograph
Based on microscopic features: Spores on average shorter than 20 µm.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thanks Judi.
By: amadej trnkoczy (amadej)
2015-10-06 05:14:15 CDT (-0500)
Gerhardt’s key
By: amadej trnkoczy (amadej)
2015-10-06 05:12:35 CDT (-0500)

Dear Bryan,

Thanks again for the information from Gerhardt’s key. It is concise and according to it a decision for P. antillarum seems straightforward. Looking ‘from my side’ Krieglsteiner doesn’t treat P. antillarum and P. semiovatus var. phalaenarum in his Panaeolus key (page 589). He is mentioning both under chapter ‘Variability’ of Panaeolus semiovatus (Withering: Fr.) Wünsche. He states: " Very similar is Panaeolus antillarum (Fr.) Dennis, which differs (from P. semiovatus) in lacking the ring and strictly centrally located porus of spores. Without ring and often growing in groups is also P. semiovatus var. phalaenarum (Fr.) Gerhardt". Now, the first one is not in our check list and the second one is. No wander I decided as I did – wrong. Thanks again.

Warmest regards

Beautiful thumbnail photo! Nice composition.
By: Judi T. (AvidAmateur)
2015-10-04 22:50:32 CDT (-0500)
I’m no authority…
By: Byrain
2015-10-03 09:23:57 CDT (-0500)

Just an amateur with Gerhardt’s keys.

“1 Veil visible as an ascending annulus; cap often typical
semiovate Panaeolus semiovatus var. semiovatus (1)
- Veil visible as dentate or appendiculate margin of the
cap or absent; cap semiglobate or campanulate . . 2
2 Veil visible as dentate or appendiculate margin of the cap
(fugacious); spores elongated, in average reaching 20 (im
in lenght, little flattened (fig. 2 c); species of temperate
…. Panaeolus semiovatus var. phalaenarum (2)
- Veil absent; spores more stocky and more flattened,
in average less 20 um (about 15-20 Lim long), similar
papilionaceus-type; species of tropical and subtropical
zones …………………… Panaeolus antillarum (3) "

Also, don’t mind me venting about the design choice this site has taken, its not your fault.

lapse/our fungi check list
By: amadej trnkoczy (amadej)
2015-10-03 05:32:42 CDT (-0500)

Dear Bryan,

Thank you for your comments and correction of my observation. If it caused some discomfort to you, please, excuse me my ignorance.

Here are my comments to your statements.

Re.: ‘var.’ not ‘ssp.’
You are right. Lapse! I had no intention to change taxonomy of this genus. Thanks for the correction.

Re.: why not just P. antillarum?
P. antillarum is not listed in the Fungi Check List of Slovenia (A.Poler, ed., Seznam Gliv Slovenije, Association of Mycological Societies of Slovenia (1998)). However, it has been reported after 1998, but only a few times and not from west Slovenia where I live. Probability that my observation is another find of this apparently rare species in Slovenia seemed to me low. The fact that the mushrooms found had no ring led me to P. semiovatus var. phallaenarum, which is listed in our check list (as Anellaria). In addition, from the literature, which I own, I found that Krieglsteiner (2010)(Ref.: 5) considers P. antillarum as a variety of P. semiovatus. Breitenbach (2000)(Ref.:4) considers P. antillarum and P. semiovatus synonimous or very closely related and Buczacki, Collins Fungi Guide, (2012) does not treat P. antillarum at all.

Anyway, to argue with the authorities like you, Kriegelsteiner, Breitenbach and Buczakih is way above my competence. May be I really had luck finding a rarity in my country :-)?

Re.: ‘…this site looks uglier every time I come here…’
Assuming that you meant MO in general I think that any particular observation among thousands is not the best place for such a comment.

All the best and thanks again

By: Byrain
2015-09-05 10:12:50 CDT (-0500)

First, its Panaeolus semiovatus var. phalaenarum, second without the veil and shorter spores looks like just P. antillarum. Third, this site looks uglier every time I come here… :(

Created: 2015-09-05 08:08:15 CDT (-0500)
Last modified: 2015-10-03 09:21:28 CDT (-0500)
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