The Velamen Radicum Is Common in the Genus Anthurium, Both in the Epiphytic and Terrestrial Species

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript addresses an intriguing topic and merits publication. Despite not being a native English speaker, I couldn't identify any grammatical errors, and the text appeared excellent to me. I usually approach my reviews with great care, but in this instance, I have no additional points to contribute or suggestions that would necessitate the authors to defend or adopt.

However, I do have a minor suggestion to offer, presented solely as a consideration. Given the authors' extensive microscopy work, it seems strange that they did not illustrate the observed velamen patterns with an image, even if just to document their presence or absence. I believe there remains an unanswered question, that authors might consider for future research. If the velamen's existence isn't correlated with plant habit, could it be linked to environmental factors such as water stress?

I propose this as a hypothesis needing exploration: plants might react to varying humidity levels (whether in the air or soil) by altering the number of velamen layers. This could result in instances of presence or absence within the same species."

Sincerely,

Élder Paiva

Author Response

Thank you for your very positive response. Regarding your suggestion of illustrations. This paper is about the occurrence of the velamen as such in a phylogenetic and ecological context. But you correctly state that structure is also important. Indeed, we are currently in the process of a detailed analysis of structural differences in the velamen. This will be a different paper and in that context there will be numerous illustrations. So we would like to keep the two separate.

Reviewer 2 Report

Comments and Suggestions for Authors Anatomical and histological studies were carried out with species of the genus Anthurium, which analyzed the occurrence of velamen in relation to habit (epiphyte vs. terretrial) and phylogenetic relatedness. It turned out that the valamen was never an ever-evolving character in the genus, but it came out and others several times. And it occurs in both epiphytic and terrestrial species. There are few studies of this character in the genre. It is an unprecedented study to discover this character in terrestrial species and in a larger number of species than was assumed. Phylogenetic studies on the topic are unknown.

Text with few considerations, update the number of species of the genus Anthurium informed, review the scientific names presented and in the first citations of the species in the text include the authors.

Comments for author File: Comments.pdf

Author Response

Thanks for the very positive response. We have now responded to all the issues you raised in the pdf you uploaded. Please check the cover letter for details

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors describe in their introduction that the literature describes the presence as a velamen as common in orchids and aroids but provides very little information on its presence in the aroids. This is an important question as, despite detailed studies of epiphytic orchids, there are few data to indicate the occurrence of this tissue in Araceae, and if present how it might rave related to success with an epiphytic life history. 

The background introduction to the function of a velamen is useful but lacking is a clear idea of how a velamen might be significant in the Araceae based on what is know about the Orchidaceae. Do the number of velamen layers have an adaptive significance? If not, then is there evidence that the range of 1-3 layers in most species significant? Is there a reason for collecting these dat for Anthurium given that there have apparently been no investigations of velamen tissues in other genera of aroids

The manuscript is heavily weighted on molecular approaches to show the phylogenetic relationships within Anthurium, adding data on the numbers of velamen layers to the plot. This to me seems unbalanced given an apparent absence of studies investigating a possible ecological role for these tissues. If the intent is to better resolve the phylogeny, would it be preferable to work wit a trait with clear adaptive significance? It would be useful to know if there are descriptions of velamen presence in other genera of aroids.

A reader is left at the end of the manuscript with an unresolved question of the significance of then velamen and its presence or loss in Anthurium. Is there added value with these data to understanding the phylogeny of this genus? 

As the authors describe, the characterization of growth forms of Anthurium species is a complicating factor. The authors describe terrestrial species which  would include secondary epiphytes and terrestrial  understory herbs as opposed to epiphytic species with no hydraulic connection to the soil. It would be interesting to show these traits on the phylogenetic graphs. Would there be greater value in adding showing the evolution lineage in relation to an functional plant trait rather than a speculative significance of the velamen?

Author Response

Thanks for your constructive criticism. In the revision we have responded to all the issues raised. For details please see the cover letter 

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The abstract of this manuscript states clearly that very little is know about the presence of a velamen in either terrestrial or epiphytic Araceae, and that acknowledges that there is little or no understanding of any functionality of these tissues. I am unclear why a single genus of Araceae was selected for study given the lack of information of the presence of a velamen in other genera of Araceae.

Are there clues from the Orchidaceae that would tell a reader more about a  the velamen as a functional trait for epiphytic species?

Anthurium is a huge genus that includes a wide range of growth forms beyond a simple separation of species as terrestrial or epiphytic. For example there are a number of large terrestrial understory herbs that would seem to differ greatly in many respects from the climbing species typically called secondary hemiepiphytes. The edits to the text do not resolve this subject.

Counts of the number of velamen layers are indentified for species in the cladogram in the second figure, but without any discussion of why this might or might not be a significant trait. Can the authors add some discussion of this measure?

Author Response

please see cover letter

Author Response File: Author Response.pdf