When: 2018-10-14

Collection location: Ricketts Glen State Park, Pennsylvania, USA [Click for map]

Who: Dave W (Dave W)

No specimen available

Spores long and thin, bigutulate.

Wondering if spore morphology is strong enough criterion to ID B. citrina?


Proposed Names

31% (2)
Recognized by sight
Based on microscopic features: I believe spore dimensions (10-14 × 4-5) rule out species of Bisporella other than citrina.
47% (2)
Recognized by sight: Undersides smooth.
Based on microscopic features
46% (2)
Recognized by sight: More microscopy is needed to get to genus.
28% (1)
Recognized by sight

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

= Observer’s choice
= Current consensus


Add Comment
Yeah, the same advice…
By: Dave W (Dave W)
2019-03-02 22:16:16 CST (-0500)

to consult Asco France was suggested to me by John Plischke.

One particularly nice thing about ascos seems to be that the micro-traits are often readily observable at 400×. AF of NA mentions thin vs. thick walled hyphae (on the outer surface of a cup) as a distinguishing character for the three genera mentioned in this discussion. With a little patience I think I can use my better scope (AmScope) to make this type of distinction. Probably also some decent razor blades and a little more practice at making a section.

i would only encourage you
By: Danny Newman (myxomop)
2019-03-02 16:18:47 CST (-0500)

to dive deeper and deeper into the discomycetes. it is a rewarding and undertraveled rabbit hole. In the meantime, however, be advised that both the UT Press book and Wikipedia are often lacking in comprehensiveness and/or accuracy. I’d recommend uploading what you have here, notes and photos, to the Ascomycetes of the World Facebook group, AscoFrance.fr, or both, and seeing what they say. I defer to the senior members of those communities completely.

Descriptions of Phaeohelotium spores…
By: Dave W (Dave W)
2019-03-02 13:51:51 CST (-0500)

are similar to Bisporella. But, according to what I have found about Phaeohelotium, occurrence on wood that is not well-rotted seems to strongly favor Bisporella here. AF of NA includes a description of P. epiphyllum, which it says occurs on leaves or needles. Also, spores for P. epiphyllum are significantly larger than the spores I found in this observation.

C du Q also includes P. umbilicatum, which it says occurs ion well-rotted wood. This species produces fruit bodies that are not described as “cup like” or even “concave”. Spores are larger than the ones in this observation.

Hymenoscyphus looks like another genus worth cionsidering (for small yellow cups). H. monticola appears to resemble the ones seen here, and habitat includes wood. Spores for this species are much larger than B. citrina.

I think Bisporella/B. citrina still looks like a promising proposal here. Wiki says there are 16 species of Phaeohelotium. Presumably, the species documented on C du Q and within AF of NA are representative of the genus, and likely to be ones that produce some of the more prominent/large fruit bodies.

I’ve adopted
By: Danny Newman (myxomop)
2018-11-01 04:05:14 CDT (-0400)

an evolving approach when it comes to this species. I think that it is largely recognizable in the field if it has been collected and microscopically confirmed from that locality previously, but am as willing as ever to call some IDs into question when there is not enough of the fruiting bodies visible in photos. In the case of this observation, you have field photography and some micrographs (though it is difficult to make out distinct structures), and this might be enough for the ID of B. citrina. If you were especially interested in cementing this ID, I would recommend heading to AscoFrance, where they may insist that you show paraphyses contents in living tissue, but I don’t think that’s so necessary given how common this species appears to be in the US.

EDIT: this comment was edited on 3/2/2019

I was hoping Danny would run across this.
By: Dave W (Dave W)
2018-10-29 19:58:02 CDT (-0400)

If the observation gets buried, I’ll draw his attention to it.

Didn’t observe many spores, but the ones I photographed are elliptic ~10-14 × 4-5, which agrees well with B. citrina. The photos are through my old scope. (Newer binocular AmScope is much better, but I can’t get good photos through a single eyepiece.) There’s a few spores that appear to be septate, with a septum positioned near the midsection; two prominent oil drops, one near each pole. This agrees well with the description of B. citrina spores found on Wikipedia.

Didn’t mention in original notes, undersides of these cups are smooth, which eliminates a few genera that feature hairy undersides/margins.

Other species of Bisporella mentioned in AF of NA have significanlty smaller spores.

Otherwise, closest thing I’ve found is Phaeohelotium epiphyllum has similar-looking small yellow fruit bodies, occasioanlly cup-shaped. C du Q lists spore dimensions very close to B. citrina, but the spore shape is different (fusiform, sometimes curved) and the habitat is different (“wood” not included). AF of NA lists the spore dimensions as significantly larger than does C du Q. I think this species is not a match for this observation.

But, I think the real problem here may be the many species that produce small cups, but don’t get mentioned in field guides or other such sources. I think I have some reasonable evidence to support B. citrina. But honestly, I don’t know enough about this area to maintain ultimate confidence, even at the level of genus.

I don’t know
By: Alan Rockefeller (Alan Rockefeller)
2018-10-29 15:15:23 CDT (-0400)

I think Danny Newman does though.

Alan, the spores very well match…
By: Dave W (Dave W)
2018-10-28 22:39:36 CDT (-0400)

the expectation for Bisporella (in particular B. citrina). Is there another genus for which spores are similar? (estimates of measurements forthcoming)

Created: 2018-10-28 16:22:04 CDT (-0400)
Last modified: 2019-03-02 22:16:17 CST (-0500)
Viewed: 139 times, last viewed: 2019-08-12 17:49:42 CDT (-0400)
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