When: 2019-03-30
Collection location: Stockbridge, Henry Co., Georgia, USA [Click for map]
Who: Chris Cassidy (cmcassidy)
Notes:
On hardwood, thallus very greenish/yellow, with fruiting warts exhibiting a yellowish ostiole at the peak. Cortex C+deep yellow to orangish-red, K- to slowly y, KC-. Ostioles also Cr, KC+reddish. Spores with several small oil drops; ~35-70 × 18-40 μm. Asci becoming very greenish-blue in Melzer’s.
Images
| User’s votes are weighted by their contribution to the site (log10 contribution). In addition, the user who created the observation gets an extra vote. | |||||||||
| Vote | Score | Weight | Users | ||||||
|---|---|---|---|---|---|---|---|---|---|
| I’d Call It That | 3.0 | 0.00 | 0 | ||||||
| Promising | 2.0 | 5.97 | 1 | (cmcassidy) | |||||
| Could Be | 1.0 | 0.00 | 0 | ||||||
| Doubtful | -1.0 | 0.00 | 0 | ||||||
| Not Likely | -2.0 | 0.00 | 0 | ||||||
| As If! | -3.0 | 0.00 | 0 | ||||||
| Overall Score sum(score * weight) / (total weight + 1) |
1.71 | 57.10% | |||||||
Comments
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That’s my only advise and best trick. But I like the idea of cutting the section in half, like opening a zip-loc baggie and pouring out the asci…
re: cutting section in half — I never thought to try that.
(And yes, Chris, I, too, have trouble judging pressure with pencil eraser. I used to use forceps tips, but I’ll be damned, the pencil eraser really does work better!)
are all good, but I will add something: if you are not trying to make a clean apothecial section, then after making an apothecial section with the rasor blade, cut it by half. This will provide a zone in hymenium from where the asci and spores will enter the mounting media while pressing the coverslit.
From “a King without Kingdom”!
I actually was reading a discussion between Zaca and yourself on slide/mount preparation and saw the pencil eraser tip that Zaca mentioned. I did try that, but to no avail, may have been pressing too hard (tough to gauge what is too hard unless you know, I guess). I’m looking forward to what these gentleman can add! Thanks
Is difficult in the best of circumstances. Those enormous asci love to rupture no matter how you do the section. Maybe zaca — the King of microscopy and much else besides :) — has some clever advice on separating Pertusaria asci without damaging them. Maybe some combination of mounting in KOH and very gentle pressure on the coverslip with a pencil eraser? Also wetting the fruiting wart before sectioning it may help? J-Dar, what’s your experience?
You’re correct. I keyed out P. texana and P. xanthodes, and read that they exhibit same chemical reactions, but the latter has only two spores per ascus. Unfortunately, my lack of a dissecting scope prevented me from getting a nice, clean section. All of the asci that I found weren’t in tact, so I couldn’t really determine whether or not there were two or more spores in them. I still have the sample, so I’m hoping to get another chance to try to scope this one a little better. Thanks again for all of your insight.
But there are three possibilities here, I think: P. texana, P. epixantha, and P. xanthodes.
P. texana supposedly often has raised ostioles, and is K+y P+o.
P. epixantha supposedly often has depressed ostioles, and is K~ P-.
P. xanthodes has only two spores per ascus instead of 8.
Thanks J-Dar.