Observation 163095: Amanita magniverrucata Thiers & Ammirati
When: 2014-04-04

Notes: Growing near Live Oak.
Cap 6.0 cm across as found; 7.0 cm in later photo when partially opened.
Spores amyloid.
Spores in Melzers ~ 9.9-12.9 X 8.9-10.2 microns
Q(range) = 1.10-1.33. Q(ave) = 1.22 n=15

Spores in Congo Red + KOH ~ 9.5-12.3 X 7.8-10.0 microns Q(range) = 1.22-1.45. Q(ave) = 1.30 n=19 They looked to me like A. magniverrucata but the spores appeared to be too round and Q values lower than reported in Rod’s website. There were similar ones found at Tomales Bay SP Sunday and I’ll be posting one of those later.

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Comments

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I suppose I should have known, but I didn’t want to guess on data…
By: R. E. Tulloss (ret)
2015-05-21 10:44:50 EDT (-0400)

included in the posting of the sequence.

Thank you for your expeditious response.

Very best,

Rod

Thanks Rod,
By: Ron Pastorino (Ronpast)
2015-05-20 19:40:52 EDT (-0400)

As with most all the oaks in this area,they were the California coastal live oak, Quercus agrifolia..
Ron

Hello, Ron.
By: R. E. Tulloss (ret)
2015-05-19 17:59:38 EDT (-0400)

This collection yielded a very good nrLSU sequence that will serve well to help identify magniverrucata genetically.

Thanks very much for sending the material.

If you can, would you let us know which Live Oak(s) was/were with the collection when it was collected?

Very best,

Rod

Thanks Ron,
By: groundhog
2014-04-18 13:26:25 EDT (-0400)

This material has been recieved and accessioned to Rods herbarium. We have scheduled it for DNA sequencing.
-Naomi

Marvelous, Ron.
By: R. E. Tulloss (ret)
2014-04-09 23:52:18 EDT (-0400)

Thanks as always.

Rod

Rod, The fat mags are in the mail.
By: Ron Pastorino (Ronpast)
2014-04-09 19:04:44 EDT (-0400)
I looked at Ron’s spore measurements in comparison to my data via a sporograph.
By: R. E. Tulloss (ret)
2014-04-08 21:42:51 EDT (-0400)

I see what Ron and Christian see. In the other page that Ron posted recently with the name magniverrucata, the spore width range is displaced (for both sets of measurements) by about 1.2 microns. At first I thought that this might result from measuring spores that were rotated 90 degrees around the longitudinal access from lateral view. However, Ron’s spore photo shows at least one spore in lateral view; and, proportionately, it is very broad. (See especially the spores photographed after staining in Congo Red.)

Changing reagent shouldn’t have this sort of impact on spore shape. Lamellae mature (in Amanita) from the stem outward to the margin. The longer spores measured in Melzer’s Reagent may have from from closer to the center of the sporeprint. Those in Congo Red may come from an area closer to the middle of a gill or even closer to the cap’s margin.

Spores from a given basidiome don’t tend to change width as much as they tend to change length (given passage of time). After maturity, length and width will both decrease; however, length will decrease faster. As a result, the Q values will decrease after maturity.

I’m not sure how maturing or aging could change the spores in Ron’s photographs into spores that match the shape of magniverrucata spores. We need to consider the possibility that at least some of the images under discussion today may not represent magniverrucata.

Since the genes posted under the name magniverrucata by Wolfe et al. (sadly) did not come from a specimen of this species, we need to rework the information on magniverrucata gene sequences. I have some samples in process now; however, the situation is such that I can’t be sure when the information will be available. (I will ask, however.)

We can just try to get ITS for some of my material of magniverrucata and compare this to an ITS sequence (or sequences) from a sample (or samples) of some of Ron’s and/or Michael’s material. Considering the spore data differences, it would be interesting to see what else may differ between Ron’s and Michael’s collections and magniverrucata.

Always more questions. Sometimes an answer.

Very best,

Rod

It’s worth mentioning
By: Christian (Christian Schwarz)
2014-04-08 12:15:43 EDT (-0400)

this article:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3061180/

Correlating fruiting date with spore size. I don’t know if it’s possible that spore size changes within a species occur from year to year if fruitings are early or delayed, but any vouchers made in coastal California in this late-fruiting spring would be valuable if anyone were to investigate that question.

I agree Christian
By: Ron Pastorino (Ronpast)
2014-04-08 12:05:56 EDT (-0400)

and I’m beginning to question my Amanita microscope techniques even though I usually have no problem with other genera.
Even in the Thiers’ monograph the spores appear to be narrower, “8.5-12.3 X 5.5-8.5 microns” for A. magniverrucata.

By: Christian (Christian Schwarz)
2014-04-08 11:50:38 EDT (-0400)

I wonder if Rod can weigh in on the variation in A. magniverrucata spores, and whether the range reported on his site is from a robust sample set or just a few fruitbodies.

The reason I’ asking is that I would almost certainly have called these A. magniverrucata in the field…

Created: 2014-04-08 11:24:30 EDT (-0400)
Last modified: 2014-04-10 00:10:25 EDT (-0400)
Viewed: 221 times, last viewed: 2016-11-24 10:50:58 EST (-0500)
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