17 September, 2023

Gymnocarpium hybrids

Gymnocarpium hybrids

Translated excerpt from C.J. William 1989, Les fougères et les plantes alliées du Canada, p. 255-256

W.H. Wagner (1966b) was the first to take an interest in a plant resulting “apparently from the crossing of G. dryopteris with G. robertianum”, a new triploid apomictic species that he named G. heterosporum.
Sarvela (1978) gave this hybrid the name G. heterosporum W.H. Wagner, indicating that it resulted from the crossing G. jessoense × robertianum.
He also described a new hybrid, G. intermedium (G. dryopteris × jessoense). Pryer (1981) reports that G. × intermedium is common where G. jessoense ssp. parvulum grows, but it is a triploid, not a tetraploid as we would expect, which makes him say that the parents are G. dryopteris ssp. disjunctum (2x) and G. jessoense ssp. parvulum (4x).
All the Gymnocarpium hybrids are recognized by the fact that most of their spores aborted. They do, however, produce some large, spherical spores that germinate and we believe that this is how they multiply, by an apomictic process, although no one has so far succeeded in growing plants to maturity. Note that if our hypothesis is correct, these hybrids are much more difficult to study than those of the genus Dryopteris, because they could have been produced at very different times and in very distant places as they are currently.
We find very large colonies of Gymnocarpium × intermedium north of the lake Superior. In some places this hybrid is much more abundant as G. jessoense ssp. parvulum.
Sarvela (1980) also described the hybrid G. dryopteris ssp. brittonianum which would result from the crossing G. dryopteris ssp. disjunctum × ssp. dryopteris. It is easy to identify and seems abundant. In this case again, we know that it is a hybrid because most of its spores abort and it reaches a larger size that the ssp. dryopteris. As with the parents, the blade is glabrous.
Pryer (1981) believes that it can also multiply by an apomictic process thanks to the few large spores it produces. We found it across Canada (Sarvela, 1980; Pryer, 1981).
Finally, let us mention G. × achriosporum Sarvela (G. dryopteris × robertianum). Hybrids of G. robertianum seem rare. The type was described based on specimens found in Sweden.
In North America, only two specimens correspond to this description; they come from Chicoutimi and Gaspé, in Quebec (Sarvela, 1981). We have not yet studied the cytological situation of this hybrid, but it should be a tetraploid, since both of its parents are tetraploids themselves.
Gymnocarpium X heterosporum is only known from type specimens found in North America; we also have it reported from one location in Finland (Sarvela, 1978). It has never been seen in Canada (Sarvela, 1980).

therein cited literature:

Pryer, K.M. 1981. Systematic studies in the genus Gymnocarpium Newm. in North America. M. Se. thesis, University of Guelph, Guelph, Ont. 166 pp.

Sarvela, J. 1978. A synopsis of the fern genus Gymnocarpium. Ann. Bot. Fenn. 15:101-106.

Sarvela, J. 1980. Gymnocarpium hybrids from Canada and Alaska. Ann. Bot. Fenn. 17:292-295.

Sarvela, J.; Britton, D.M.; Pryer, K. 1981. Studies on the Gymnocarpium robertianum complex in North America. Rhodora 83:421-431.

Wagner, W.H. 1966b. New data on North American oak ferns, Gymnocarpium. Rhodora 68:121-138.

Posted on 17 September, 2023 11:46 by erwin_pteridophilos erwin_pteridophilos | 1 comment | Leave a comment

02 December, 2021

Likely wrong identifications of Polystichum × potteri in Vermont, USA and Nova Scotia, Canada

This post is written to clear some apparent wrong IDs of the fern hybrid Polystichum × potteri = Polystichum acrostichoides × braunii done and caused by me.
Please keep in mind that some, but not all my suggestions will be erroneous.

13 Observations which are currently, on 02.12.2021, identified as Polystichum × potteri


@choess @cgbb2004 @cchapman @seanblaney @charlie @connieyoungstrom @dbmcc09 @ebsessa @hayleykolding @hcray @jwatkins92 @msundue @pamdarrow @randyfredericks @michael_oldham @eralverson @david1945wagner @grazing @rroutledge

Since i am well familiar with several kinds of the genus Polystichum, in especial the ones native to Europe and northern North America, i added lots of IDs. In course of that i reviewed several kinds of hybrids as well, which in turn are quite hard to detect and to identify, in especial upon photos.

Why do i expect, that some IDs as the hybrid P. × potteri will likely be erroneous, and what was right instead?
Well, P. braunii, the one parental kind of the hybrid with (nearby) bi-pinnate fronds is ± uniform in my home region in Styria, Austria, as well as in major part of the native range.
The only, but slight exception was, that very large grown individuals do tend to have clearly bi-pinnate blades, and that the basal pinnae may grow somewhat longer than for usual.
However, there is a slight exception with the population of P. braunii native to eastern USA and Canada.
So far i noted this correctly, in that region are two types of individuals, the ones which look quite the same as others of distant populations, and the ones with minor, yet visible differences.

What is differing between "usually looking" and deviating types in eastern North America?
This is nothing but my personal perception by watching photos, however, i am best trained in recognizing visual patterns. [thus, no supporter of AI suggestions - well, another story]
I repeatedly recognized that some individuals of P. braunii had slightly darker green, glossier, and "rigid" looking fronds, combined with somewhat less divided pinnae, so that the pinnulae (pinnae of 2nd order) are adnate by a wider base than "for usual".
Although i do not know if these slightly differing characters were the same with Polystichum braunii var. purshii Fernald, i wouldn't support this distinction, at least right now.

Individuals as described above, which do look like influenced in appearance by their relative Polystichum acrostichoides do make the separation from true hybrids P. × potteri even harder and may or will have caused my wrong IDs.

What do i attend now?
I liked to critically review all obss. identified as Polystichum × potteri, and alert all engaged and interested iNat members.
I am sorry for having provoked erroneous IDs in case!

Best regards to all

the one who loves ferns - as well as other living creatures!

Posted on 02 December, 2021 11:19 by erwin_pteridophilos erwin_pteridophilos | 1 comment | Leave a comment

24 March, 2020

„Please tell me how to collect, if I happen to find a colony next time I see Equisetum?“

Well, that is indeed an important question!

Since occurrence of genus Stamnaria, including asexually reproducing Titaeospora stage, seem to be rather rare in western part of USA, yet North America, any collecting person should avoid needless exploitation of infected horsetails, as well as the fungi.
In fact i don’t know about accurate frequency and sizes of horsetail populations being inhabited by (partially) parasitic genus Stamnaria, but let’s be cautious anyway.

Collecting itself is easy: cut aerial horsetail shoots right below lowest segment, named „internode“, which bears a usable stage of Stamnaria. After releasing vegetative and/or generative kinds of reproductive spores, the infected part and above will die anyway.
Thereafter do drie sampled parts in a dry room apart of sunlight, uncovered for a few days as water will evaporate freely, thus pieces not stapled but side by side. You may remove not infected internodes before, or therafter.

Please do only collect in case the horsetail occurrence appears not too small, and visible infections are not scarce, but numerous, to avoid exploitation of hosts and inhabiting ascomycetes. Otherwise it was preferable to try gathering well done photos so far. For sure decision concerning collections do depend on subjective estimation and evaluation, up to yourself.

What stage of fungus is usable at all?
In general, characteristicly blackened shoot segments may indicate infection by some Stamnaria. At close view, visible without magnification, there shall at least be clearly visible parallel splits along furrows of segments, where the rigid outer skin is slightly lifted, and sometimes hardly visible masses of spores ooze out.

This ist the first stage of use, as such vegetative conidia of Titaeospora type will prove true as member of genus Stamnaria, despite i might not identify distinct species‘ of. However, molecular analyzation and comparison might reveal specific ID in case of enough known sequences.

At later stage such fungi do break out small, for usual longitudinal pieces of epidermis, where masses of conidia and generative fruitbodies will be borne. Such pieces of skin do for usual adhere to shoot surface, caused little holes are visible then and thereafter, even when internodes are dead and bleached, the causing fungus has gone.

In best case, yet far too rare, you may find fully mature, cup-shaped fruitbodies, so named apothecia. These are bright yellow coloured and opened when soaked in water, ready to release their generative ascospores.
When dried, these do shrivel, colour changing to orange or orange brown. Rehydration goes the most quickly by adding water, so fruitbodies will soon start releasing spores in case of maturity.
Apothecia are short lived and will be grown seasonally, depending on species and climate.

I could identify such in case of sufficient maturity on characters of sporangia, so named asci, and spores borne within. So these could be sorted to species known to me, or as well get recognised as further knew detected species, sure it is possible.

Treatment of ready collection:
You could send ready samplings when segments got dried after some days, so these wouldn’t be destroyed by mould fungi. Perhaps you do know scientific institutions who liked to identify specimen and to preserve in their collection.
I surely shared my knowledge to ensure right ID according to my experience, as several species‘ known to me are still not published, and many preserved specimen are wrongly identified for lacking knowledge and usual mixings up.

Another chance was sending to me for ID and sharing with botanical institutions, still i need equipment like microscope, or to visit a propper instituion at university myself.

Just do ask me in case of further questions i missed to answer here.

Best regards and wishes
Erwin Gruber

Posted on 24 March, 2020 10:21 by erwin_pteridophilos erwin_pteridophilos | 2 comments | Leave a comment

22 March, 2020

New findings of Stamnaria sp. on Equisetum hyemale

I wanted to add the following explanation to this https://www.inaturalist.org/observations/40254088

As it got quite long, i present it here, so anyone who is interested may read and discuss about.
This is as well starting my project concerning the ascomycete genus https://www.inaturalist.org/taxa/366203-Stamnaria which still needs to be created.

@gennadiy @julia_shner @jameskm @radekwalkowiak

I may not know if this parasitic fungus here does represent https://www.inaturalist.org/taxa/366211-Stamnaria-americana without proving characters of sporangia, so named asci, and spores thoroughly.
I do not know of any record, respectively collection of that species from Russia up to day, and prior identifications need revision in any case.

Likewise fungi inhabiting Equisetum hyemale may as well belong to, regrettably still not validly published, "Stamnaria laetissima (Cesati) Gruber [me]" comb. ined.
Basing name is Peziza laetissima Cesati (1846) in G. L. Rabenhorst, Herbarium Vivum Mycologicum no. 1024, collected in South Tyrol, Italy on Equisetum ramosissimum.

S. laetissima got apparently a wide range, inhabiting different species of Equisetum subgenus Hippochaete. These fungi do look quite the same as with S. americana, but do differ in amyloid, J+ staining structure at ascus apex, sizes and Q of ascospores, and main generative fruiting period.

I differed between the nominative type, proved to inhabit Equisetum ramosissimum [+ subsp. debile?], E. hyemale subsp. hyemale [+ subsp. affine ?] and E. laevigatum in North America, and "Stamnaria laetissima (Ces.) subsp. tenuispora".

According to my investigations, the nominative "subsp. laetissima" was distributed by several exsiccata, which i do not cite here, but may share details in case wished, just dare to ask for. Links following separately.
For sure i may not exclude there was further infraspecific or even specific differentiation.

The latter "subsp. tenuispora", characterised by clearly narrower ascospores, was collected mainly in NE Europe, just once in E England, near Scarborough, coll. G. E. Massee, all found on E. hyemale.
I reidentified collections from southern Finland, F. de Thümen, Mycotheca Universalis no. 125; and Russia, Karelia, H. Roivainen, Mycotheca Fennica no. 878; near Kingisepp, coll. V. Melnik. Links following separately.

Considering native ranges as known up to day by me, this report here could as well represent S. laetissima, as with several other specifically unidentified, new findings on host Equisetum hyemale in Russia, reported at iNaturalist.
Thus i needed to prove specific characters of Asci and spores to clear identity of all new findings.

Please do ask me in case of interest and questions about.

Erwin Gruber

Posted on 22 March, 2020 09:03 by erwin_pteridophilos erwin_pteridophilos | 2 comments | Leave a comment

13 December, 2015

Naming and typification of Polystichum lonchitis × setiferum

The fern hybrid Polystichum lonchitis × setiferum was published in 1904 by Halácsy as "Aspidium lonchitiforme", apparently collected in Taygetos Mountains, Pelopponesia, Greece in 1898.




Just a single hybrid has ever been reported from Taygetos Mountains, where Polystichum aculeatum as treated nowadays seems to be absent, P. setiferum, treated by Halácsy as "aculeatum" is commonly distributed.
The author of Aspidium lochitiforme stated that A. lobatum, our P. aculeatum was absent from Peloponnesia in opposite to A. aculeatum, our P. setiferum.
Anne Sleep repeated the same situation in her doctoral thesis in 1966 after having searched for this hybrid in Taygetos Mountains without success.
Since both parental species, P. lonchitis and setiferum are present there, Sleep accepted Polystichum × lonchitiforme as valid name for the hybrid, but without cytologic examination to exclude the identic looking hybrid P. aculeatum × lonchitis, P. × illyricum.

The type material from Greece does indeed look the same as the latter hybrid, thus the only evidence that it could be lonchitis × setiferum is the apparent absence of aculeatum at Taygetos.
We may not exclude that aculeatum is or was present where the single type of A. lonchitiforme has been collected, no precise locality has been noted.
If that was not enough, Halácsy wrote to have found the single hybrid within a great number of P. lonchitis sendt by Heldreich for distribution in Herbarium graecum normale.
Probably the type originates from the Greek mountains, but i would even not exclude mixing up with sheets collected elsewhere, this way P. × illyricum might have been labelled with wrong origine.
In other words the type of A. lonchitiforme might turn out to be another synonym to P. × illyricum, so far the number of chromosomes could be testified.
This seems to be simply impossible, thus i think we will have to accept P. × lonchitiforme as binomen for P. lonchitis × setiferum, no matter if dubious or not.

The first cytologic evidence of true hybrid P. lonchitis × setiferum was done by Anne Sleep in 1976, the ferns were found in region of "Ben Bulbin" in counties Sligo and Leitrim, Ireland.

A single later report of the same hybrid came from Hungary, but the Irish occurrence seems to be the sole known present at time.
For this reason i chose the English names "Irish shield fern" and "Irish holly fern" for the hybrid.

Posted on 13 December, 2015 17:00 by erwin_pteridophilos erwin_pteridophilos | 0 comments | Leave a comment

15 February, 2015

Taxonomic concepts about Alpine lady ferns in Europe and America

I want to try a short discussion about different taxonomic concepts concerning European and American population / type of Alpine lady fern, and to explain those concepts here.
There are obviousely two different kinds of Alpine lady fern in Europe and mainly western North America, and at least another one in eastern Asia which is not discussed here at time.
These two were variousely named scientifically as Athyrium alpestre, A. distentifolium and A. americanum.
We may imagine there will be some differences between two populations separated completely for considerable time, still it stays rather a question of subjective estimation and evaluation to decide about treating them as distinct species, or infraspecific varieties or subspecies.
So far not accepted as separate species, i would clearly prefer to regard European and American Alpine lady ferns as distinct subspecies isolated from each other, rather than as varieties, this rank and term might better be reserved for sympatric populations in my mind.
Different rankings as separate species or subspp. / vars. is one reason for diverging taxonomic concepts and namings.
Obviousely there is reason for some experts, to regard the oldest specific name as not valid - Aspidium alpestre Hoppe, 1805, but to prefer the later published one - Athyrium distentifolium Tausch ex Opiz, 1820.
In fact i do not know the exact reasons to reject Hoppe's older specific name, or if this interpretation is right or wrong, at least other botanists did and do accept it, treating the younger name distentifolium as synonym.
Maybe there was done a final decision in this case, i do not know of one.
Acceptance of the older name, or rejecting as invalid in favour of the later one leaded to further taxonomic combinations and confusion.
Alltogether i may consider 4 different taxonomic concepts, when including the ones to differ as varieties there are 6 different possibilities, all seem to have been applied by authors at some time.

1st concept: specific name "distentifolium" valid, "alpestre" invalid, synonymous, taxa separated as distinct species:

Europe: Athyrium distentifolium Tausch ex Opiz, 1820
North Am.: Athyrium americanum (Butters) Maxon, 1918

2nd concept: specific name "distentifolium" valid, "alpestre" invalid, synonymous, taxa separated as subspecies or varieties:

Europe: A. distentifolium subsp. / var. distentifolium Tausch ex Opiz, 1820
North Am.: A. distentifolium subsp. americanum (Butters) Hulten
North Am.: A. distentifolium var. americanum (Butters) Cronquist or (Butters) B. Boivin ?

3rd concept: specific name "alpestre" valid, "distentifolium" synonymous, taxa separated as distinct species:

Europe: A. alpestre (Hoppe) Clairv. (ex Moore ?) or (Hoppe) Nyl. ex ? Milde
North Am.: A. americanum (Butters) Maxon, 1918

4th concept: specific name "alpestre" valid, "distentifolium" synonymous, taxa separated as subspecies or varieties:

Europe: A. alpestre subsp. / var. alpestre (Hoppe) Clairv. (ex Moore ?) or (Hoppe) Nyl. ex ? Milde
North Am.: A. alpestre subsp. americanum (Butters) Lellinger
North Am.: A. alpestre var. americanum Butters, 1917

At time we got added the taxa of the first concept, Athyrium americanum and distentifolium at iNaturalist database, suggesting that Hoppe's older name was invalid.

http://www.inaturalist.org/taxa/117385-Athyrium-americanum maximal 4 at time
http://www.inaturalist.org/taxa/75694-Athyrium-distentifolium 1 (2 erron. ID) at time

In addition there is A. distentifolium var. americanum from 2nd concept, with some added observations as well.

http://www.inaturalist.org/taxa/80451-Athyrium-distentifolium-americanum 5 (6) at time

There should be done a decision between both now represented taxonomic concepts for to lead together all observations of the American population.
Any constructive contributions and comments to this are appreciated !

Posted on 15 February, 2015 19:59 by erwin_pteridophilos erwin_pteridophilos | 1 observation | 1 comment | Leave a comment