Some characters of Brownseya

[choess]

I started in on what I thought would be a simple housekeeping proposal (recognition of Brownseya to maintain monophyly of Pseudolycopodiella) and as usual, nothing is simple to undertake.

Chen et al. 2021 seems to be internally contradictory as regards the sporangia of Brownseya serpentina. "The non-monophyly of Lycopodiella sensu Øllgaard (1987) suggests that isovalvate sporangia shared by Pseudolycopodiella caroliniana and L. serpentina are homoplastic," but in the diagnosis of Brownseya, that genus is stated to have anisovalvate sporangia, which is given as one of the characters separating it from Pseudolycopodiella s.s. Burnard et al. 2016 also report L. serpentina as having isovalvate sporangia, which I presume is correct.

In that case, Brownseya can be separated from Pseudolycopodiella s.s. on the basis of phyllotaxy (10 ranks in the former, usually less in the latter, although P. contexta and P. krameriana get up to 8 or 9 ranks) and the visibility of sporophylls prior to dehiscence. I take it this latter character refers to the tendency of sporophylls in Pseudolycopodiella s.s. to go from ascending to spreading as they mature. (Note that P. limosa, noted as similar to B. serpentina but for which no molecular data is as yet available, belongs in Pseudolycopodiella s.s. if these characters hold.)

Please let me know if I am correctly diagnosing the genera here and I would be happy to finish writing up the Brownseya proposal.

[DrAshleyField]

The taxonomic diagnosis of Brownseya from Pseudolycopodiella in Chen et al. 2021 is incorrect with regards to sporangial valves. The discussion of homoplasy of isovalvate sporangia between Brownseya from Pseudolycopodiella, and then using anisovalvate sporangia as a diagnostic character of Brownseya from Pseudolycopodiella is internally contradictory. All material of serpentina and limosa that I have examined have isovalvate sporangia. The presence (or absence) of veinal mucilage canals (a feature of Pseudolycopodiella) was not examined.

The key characteristics for Brownseya in Chen et al. 2021 are "Sporophylls arranged in alternating whorls of 5 or more, forming 10 or more longitudinal ranks; sporangia anisovalvate, axillary, hidden by free sporophylls until dehiscence=4" and "Tropophylls clearly longer than sporophylls"

In material of serpentina I have examined, the sporangia are isovalvate (not anisovalvate), the sporangia and the sporophyll size range is nested in the trophophyll size range (not smaller than), the sporophyll arrangement ranges from alternating subwhorls of 3 to 5 [=longitudinal ranks of 6-10] (not as described) and the sporophylls begin to spread prior to sporangia dehiscence, making them visible.

Assuming limosa were to be placed in Brownseya (not yet combined), the sporangia are isovalvate (not anisovalvate), the sporophyll and trophophyll size would be more or less correct (not including the reduced trophophylls on the undersurface or peduncle), the sporophyll arrangement ranges from subworls of 3 to 5 [=6 to 10 longitudinal ranks] (not as described) and the sporophylls begin to spread prior to dehiscence of the sporangia (+the sporangia are visible prior to spread).

At present, I am unable to diagnose Brownseya based on the characters presented by Chen et al. (2021). Also, I am unable to reproduce the tree topology of Burnard et al. (2016) or Chen et al. (2021), but I am using a different sampling and marker set.

[choess]

Thank you, that is an extremely helpful and thorough answer. I will have to retract my intention of writing the proposal. I had hoped this would be a simple fix to achieve monophyly in the Lycopodielloideae, but my lack of familiarity with these species would not allow me to address this soundly. (I might play a bit with the tree topology, though.)

For those, like me, who were wondering if the veinal mucilage canals fell under the jurisdiction of the Engineers or the Post Office, Jim Bruce's 1976 paper https://www.jstor.org/stable/2441916 seems to be the definitive treatment of the subject. They lie abaxial to the vein when present; their presence seems to have been verified in the trophophylls of most or all of the North American diploid Lycopodiella s.s. and their absence in Pseudolycopodiella caroliniana and P. meridionalis.

[gonggashan88]

Hello, guys! Thanks for bringing attention to the aniso/isovalvate sporangia. It is true that the morphology of the few related species needs more attention in future. As we admitted in the paper, "the morphological features of the genus may need to be clarified in future."

Well, distinguishing Brownseya from Pseuodolocypodiella did not seem to be a big issue, did it? The attention to the more subtle difference between Brownseya (L. serpentina) and (other species of) Lycopodiella had not been paid before our work. The paraphyly of Brownseya in relation to either Lycopodiella or Pseuodolocypodiella is quite convincing. If you were unable to reproduce our results about the paraphyly using your data, why not try to sample Burnard et al.'s (2016)] markers or our markers? It would be simple enough, wouldn't it?

In Chen et al. (2022) we said that Brownseya might contain 2-4 species and one of them might be L. limosa. Hope it is simple enough to find out by sequencing some loci of it.

Best to you all.

[choess]

For the record, I didn't mean to suggest that Brownseya shouldn't be recognized; it's just that it is morphologically complex enough that I don't feel confident handling it on my own, although I thought in the beginning that I might be able to. I only cited P. contexta and P. krameriana because I started looking very carefully at the other morphological characters when the sporangial character broke down; comparing Brownseya directly to sometimes obscure New World taxa is not something that I would expect to happen in real life, and I don't think that would have been reasonable to expect in the original paper.

I don't think it is fatal to Brownseya if the diagnosis isn't quite clean at present; other than spore count, I don't think there are any gross morphological characters that unambiguously separate any Myriopteris from any Cheilanthes s.s. (as far as I know), and I don't think anyone is very troubled by that. And anyhow, it might get more clear once the presence or absence of mucilage canals is determined, for instance. I have seen B. serpentina cited as a reason to lump rather than split in Lycopodielloideae, so I want to make sure whatever gets written into PPG II for circumscription stands up to refutation.

I just ran your Appendix S1 file though MegaX and Brownseya came out where it should between Lateristachys and Palhinhaea, so that's probably just a sampling issue.

[gonggashan88]

Thanks for your response and for running the data to confirm the relationships of *Brownseya*. I personally can/prefer to tolerate morphologically less clear diagnosis as long as evolutionary evidence is strong. DNA data don't lie and are more objective, although human errors are possible in data generation and analysis.

…

--- Best wishes, Libing Li-Bing Zhang, Dr. nat., Curator, Missouri Botanical Garden www.mobot.org/Zhang.shtml

On Sat, Aug 5, 2023 at 11:51 AM choess ***@***.***> wrote: For the record, I didn't mean to suggest that *Brownseya* shouldn't be recognized; it's just that it is morphologically complex enough that I don't feel confident handling it on my own, although I thought in the beginning that I might be able to. I only cited *P. contexta* and *P. krameriana* because I started looking very carefully at the other morphological characters when the sporangial character broke down; comparing *Brownseya* directly to sometimes obscure New World taxa is not something that I would expect to happen in real life, and I don't think that would have been reasonable to expect in the original paper. I don't think it is fatal to *Brownseya* if the diagnosis isn't quite clean at present; other than spore count, I don't think there are any gross morphological characters that unambiguously separate any *Myriopteris* from any *Cheilanthes* s.s. (as far as I know), and I don't think anyone is very troubled by that. And anyhow, it might get more clear once the presence or absence of mucilage canals is determined, for instance. I have seen *B. serpentina* cited as a reason to lump rather than split in Lycopodielloideae, so I want to make sure whatever gets written into PPG II for circumscription stands up to refutation. I just ran your Appendix S1 file though MegaX and *Brownseya* came out where it should between *Lateristachys* and *Palhinhaea*, so that's probably just a sampling issue. — Reply to this email directly, view it on GitHub <#13 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6HTSGMUCIB5L4CUS3CO4RDXTZ2YBANCNFSM6AAAAAAZHFF5QY> . You are receiving this because you commented.Message ID: ***@***.***>

[choess]

And I am sorry--I realized my email implicitly suggested Chen et al. 2021 was not good, which was not at all my intent, only to highlight my own limitations as someone not familiar with Brownseya in person. I think it is not uncommon to have little discrepancies in the literature that specialists are aware of and the rest of us aren't, but this is a good opportunity to work on them! I would definitely prefer to be able to separate Brownseya in PPG II rather than have a polyphyletic Pseudolycopodiella or try to lump Palhinhaea etc.

I am feeling more optimistic about developing a diagnosis--the other characters discussed from couplet 3 of Chen et al. are there to separate Brownseya from Lycopodiella, so they're superfluous to the isovalvate/anisovalvate sporangium. Many American and African Pseudolycopodiella have strongly anisophyllous leaves on the horizontal shoot, so it's really a few of those South American taxa that seem superficially closest to Brownseya. (I'm making heavy use here of Kelsey Cook's unpublished thesis on New World Pseudolycopodiella.) This may not be so bad to fix.

[gonggashan88]

No worries. Thanks for pointing out the isovalvate/anisovalvate issue we missed. Hopefully more evidence will be uncovered in the near future. Thanks for your service to the community by writing up proposals.

…

--- Best wishes, Libing Li-Bing Zhang, Dr. nat., Curator, Missouri Botanical Garden www.mobot.org/Zhang.shtml

On Sat, Aug 5, 2023 at 6:34 PM choess ***@***.***> wrote: And I am sorry--I realized my email implicitly suggested Chen et al. 2021 was not good, which was not at all my intent, only to highlight my own limitations as someone not familiar with *Brownseya* in person. I think it is not uncommon to have little discrepancies in the literature that specialists are aware of and the rest of us aren't, but this is a good opportunity to work on them! I would definitely prefer to be able to separate *Brownseya* in PPG II rather than have a polyphyletic *Pseudolycopodiella* or try to lump *Palhinhaea* etc. I am feeling more optimistic about developing a diagnosis--the other characters discussed from couplet 3 of Chen et al. are there to separate *Brownseya* from *Lycopodiella*, so they're superfluous to the isovalvate/anisovalvate sporangium. Many American and African *Pseudolycopodiella* have strongly anisophyllous leaves on the horizontal shoot, so it's really a few of those South American taxa that seem superficially closest to *Brownseya*. (I'm making heavy use here of Kelsey Cook's unpublished thesis <https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=miami1438305739&disposition=inline> on New World *Pseudolycopodiella*.) This may not be so bad to fix. — Reply to this email directly, view it on GitHub <#13 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6HTSGPIBMIS554LCCSO5ZLXT3KBPANCNFSM6AAAAAAZHFF5QY> . You are receiving this because you commented.Message ID: ***@***.***>