An Extraordinary Rosette and Resurrection New Spikemoss, Selaginella iridescens (Selaginellaceae) from Hainan Island, China^†

Round 1

Reviewer 1 Report

This is sound study evidencing an interesting finding of a new rosette-forming Selaginella species in Hainan Island. The new species is very well described based on detailed morphological characters and placed in the framework of a molecular phylogeny. Illustrations are high quality and support the recognition of this new species. I marked the manuscript with 107 comments and suggestions, using the track changes tool in the PDF.

The only critical issue is the IUCN assessment that is not led correctly. A IUCN assessment must be based on criteria validating at least 2 conditions. These criteria and conditions must be cited and supported  by an explanation, so that the proposed conservation status will be reliable.

Other issues:

• Introduction: a short background on the Selaginella species diversity currently known in Hainan would improve the introduction. Are any of the other rosette-forming species already known in the island? Hainan is quite a small island: is it the first time that the new species was collected, or do you know some older collections of this species? It is worth mentioning the case, and in the latter case, it would be useful to know what species name was so far (mis)applied to the new species.
• I advise to mention the authorities for names at first occurrence in the text.
• Figure numbers are sometimes erroneous in the text and must be checked/corrected everywhere.
• Figure 1 (map) would be advantageously replaced by a more detailed map focusing on Hainan and placing more accurately the site of collection.

Comments for author File: Comments.pdf

Author Response

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Reviewer 2 Report

The manuscript by Yang et al. intends to publish a new Selaginella species from Hainan, China. The morphological distinctions observed among the new species and related species significantly contribute to this taxonomically complex genus knowledge. Furthermore, the phylogeny based on rbcL confirms this species's phylogenetic position and the parallel evolution of rosette growth form.

The whole paper is well written and has excellent content. However, a few unclear points have arisen from insufficient background information, thus made readers not fully understand the bases of those conclusions. For example, in the morphological study, there are distinct gaps in all morphological characters listed. If those morphological data come from literature or very few specimens, how much confidence is there?  Where is the variation range found on how many measurements? Second, in the phylogenetic tree, the nucleotide variation and branch length are not indicated. How many nucleotide differences among related species are found? If closed related species differ in only a few nucleotides, the branching pattern might not reflect their true relationships.

The assignment of the conservation status of this new species is premature. It might be " VU " based on the current data. But the " DD " status might be better as much data is not available for this species. For example, what is the basis of judging the current population to be the only one? Did all the similar habits in Hainan have been surveyed? And did all the herbaria in this region are checked?

In addition, some sentences or words could be more clear or better modified. For example, the sentence "The monophyly of Selaginella has rarely been doubted, in contrast its infrageneric classification has been contentious." on lines 29 to 30 is to be reworded as it is identical with a sentence in Abstract of Reference 6 cited in this manuscript. Second, if both ends of measurement are approximate, the "ca." is better used on both numbers. Otherwise, readers might suspect the second number is definite. Third, some of the corresponding descriptions in each species in Table 2 are missing. Fourth, reference 3 is better than reference 4 for citing character evolution study.

Author Response

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Reviewer 3 Report

I have no important comments for the manucript, it seems to me that it is well written and well supported from a methodological point of view. An excellent work with experimental and theoretical support.

• There are minimal details in the text, which can be easily corrected
• Maybe indicate on the map where China is
• Is there any possibility that the species is actually a hybrid or ploliploid? 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx