PhyscoHunt's Boletim

Dear PhyscoHunters,

Starting in 2018 we have requested your cooperation in our goblet moss hunt and finally we are ready to share some of the results and findings that you all have contributed to gather. During the past months, the members of the team at UCONN and Texas Tech have been receiving your samples, vouchered them, cultured the spores when possible, and compared their genetic variation to determine their ancestry. Let us begin by emphasizing that the contribution of many iNaturalist users and the members of the PhyscoHunt initiative have made a difference. Your participation has increased the amount and the diversity of the data we have analyzed and we are sincerely thankful for your time!

Quick background recap

Our original aim with this project was to identify genetic variation within the goblet moss, Physcomitrium pyriforme in North America an Europe and, in particular, whether polyploidization (shifts in genome size) played an important role in the origin and diversification of this moss. We chose it as a model organism because moss evolution is relatively little known in the broader context of plant science, and a strong influence in polyploidization was suspected. The main questions we were posing, however, are not only relevant to a tiny moss, but they also enrich our general knowledge on how plants (all of them, including the tiny ones) evolve. Physcomitrium has as a couple of extra advantages: it can be cultured in lab conditions, so even with a small sample of viable spores, we can, potentially, produce a large amount of tissue to generate genomic libraries. The last final advantage of this choice is its wide range and collection easiness, particularly in Eastern North America. That's why we asked for your help!

Your contributions

PhyscoHunt was active mostly from 2018 to 2020 (although we are still happy to receive Pacific or European samples!). During this period of time more than a hundred iNaturalist profiles joined the project to stay in touch and receive updates. We are delighted to see that enthusiasm for a tiny moss! We monitored all the new Physcomitrium observations that popped up, especially during spring time of the past seasons, and tried to contact the user that had found goblet moss. If you are reading this, chances are that we requested your help after we saw one of these observations.

Overview of the PhyscoHunt sample gathering figures

All in all, we attempted to contact the observers of over 800 Physco observations, corresponding to a total of 279 iNat profiles. We received an answer from 130 of these profiles, and for many of them, this was the beginning of the hunt. Sometimes the collection of the sample was not possible, but often our most committed Physcohunters would return to the right location, monitor the colonies until the capsules were ripe, or look further for new samples in the whereabouts of the location.

Our lab at UCONN received about 120 Physcomitrium samples directly from you. Every single sample that we received (even if we could not culture their spores) has become a scientific specimen of the CONN herbarium (publicly available for all researchers). This means it can always be used in future studies to investigate its morphological traits or re-extract genetic material. These vouchers will still be very useful in the imminent taxonomic studies.

The next step of the process was to recover some spores and culture them. Not all spores made it into this last step for different reasons. For example, we realized that sometimes capsules would open during shipment, and maybe you realized that we modified the flyer last year, precisely to take this into account. Once that the cultures had grown enough, they were sent to the team at Texas Tech to sequence up to 600 genes from each of the accessions. A total of 65 samples made it to this last step.

Results overview

Although we will not be sharing here all the details of our research yet, there are a couple of relevant outcomes that we wanted to post on the project blog. These results have been already communicated in a couple of virtual botanical conferences during the summer (BL2021 and Botany2021). We also think that, as iNaturalist users, you are mostly interested in knowing what have we learned about these organisms that you collected growing on your backyard (sometimes, quite literally).

One name, several species

One of the original hypotheses of the project has been validated by our results. There is a lot going on under the umbrella name "Physcomitrium pyriforme". It is definitely one of the easiest mosses to identify and spot, but it turns out that it is not just one moss. We have detected that in Eastern North America there are at least three distinct goblet moss species (haplotypes) coexisting. Up to date, they seem to be morphologically indistinguishable (these are called "cryptic species"), but the truth is that nobody in recent times has attempted to discriminate different species within this complex. Notably, Elizabeth Britton (1858-1934) already proposed a taxonomic treatment of North American goblet mosses splitting what today we call Physcomitrium pyriforme into several taxa. Her approach was ultimately abandoned, but maybe she was at least partially right. We will hopefully know sometime soon.

Coexistence in sympatry

One of the most intriguing implications of the results we are obtaining is that the three hidden (potentially cryptic) American goblet moss species do not show a strong geographic pattern. It seems that within the Eastern United States, the three of them are potentially present in your area, regardless of whether you are in Vermont, Ohio, or Alabama. This was definitely a possibility we expected, but perhaps not the most straightforward, since speciation events are often facilitated by geographic isolation. We cannot discard that the three species, although present in the same areas, show other type of ecological niche specialization (for example, microecological conditions) but we can't be sure yet. These lineages do not remain unchanged, we have detected that some degree of admixture is quite common, but still, the three lineages seem to have their own proper distinctiveness, same as different oak species hybridize, but they keep their own distinctiveness.

This maps show as circles the goblet moss specimens we have used in our study. The different colors (pink, orange, and green) represent the different haplotypes (potentially cryptic species) we detected. Circles with different colors represent samples that had some degree of mix of the different haplotypes. It seems that all haplotypes can be found across the latitudinal and longitudinal gradient of goblet moss distributions. There are areas with a lot of overlapped specimens and they always have the three haplotypes present. Remember that even if you can't see your location on this map, your sample is vouchered as a herbarium specimen. (Image prepared by Lindsay Williams)

A tangled family tree

As we said, polyploidy research was one of the targets of the project. The whole genus Physcomitrium has species with different genome sizes and chromosome numbers, suggesting that their genomes are not static. One of the sources of polyploidy is hybridization, which is extremely common in flowering plants, but an overlooked mechanism in mosses. Our research joins new discoveries from bryology that show that polyploidy might very well be a universal driving force of plant evolution, regardless their size and complexity. In particular, we have detected that several Physcomitrium species have a hybrid origin, and sometimes the parental lineage corresponds, or seems very close, to one of the Physcomitrium pyriforme lineages we mentioned above.

Further steps

We plan to continue our research with goblet mosses and try to resolve some of the pending questions. In particular, we need to verify whether the three cryptic species are indeed cryptic or whether they have some subtle but clear morphological characters that can be used to tell them apart. Also, our sampling did have a clear bias towards Eastern North America. Although Physcomitrium pyriforme mosses are present in Europe and Western North America, the amount of observations and samples coming from these areas is lower and we still need to determine how many (and which) genetic profiles are present there. It seems that goblet mosses will continue teaching us how these small plants evolve and diversify.

Once again, we are very thankful for your support and contribution to this project. We hope next time you spot Physcomitrium or other mosses you are more aware of the hidden diversity that surrounds us everywhere.

Dear Physcohunters,

We have received some questions regarding the initiative during the current pandemic, and in particular whether we are still accepting samples. Given that our personal field work travel plans have become impossible due to the current public health concerns, the participation of PhyscoHunt contributors will be now more important than ever.

If your circumstances and restrictions implemented by the local authorities allow you to collect Physcomitrium safely, we will be very thankful if you can send us your samples.

Please contact me (@rmedina) via direct message for an updated postal address.

Take good care of yourselves and best wishes

Rafa

Greetings, physcohunters!

All the PhyscoHunt observations as of January 2020

After several months, we were due for an update to all the followers of the projects and the many enthusiast bryo-lovers who contributed with some Physcomitrium samples during 2019. We are very thankful for the reception of the campaign and the 71 members of the projects so far. We had several intense months with many of you contacting us for identifications or to share your samples and as we move forward and think about the 2020 campaign, we want to share a short recap of how things have been going in the labs once we received your mosses.

During 2019 we have received 61 Physcomitrium samples from 26 PhyscoHunt contributors, and we are grateful to every single one of them! It has been exciting to know of so many naturalists paying more close attention to mosses around them. Most of these samples were collected in North America. We have received samples from 15 states (Connecticut, Florida, Illinois, Kentucky, Mississippi, Missouri, New York, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas, Vermont, and Virginia), plus some samples from Canada, France, and the UK!

We were very impressed by how carefully many of you shipped your samples. Remember to include with as much detail as possible all the locality information!

Dr. Patel (UConn) examining some PhyscoHunt samples and propagating moss cultures

Upon reception we transfer the samples to acid-free packages to voucher them and we examine their content to confirm the ID. Most frequently, when the samples are sent according to the training guidelines, they contain capsules full of spores that are ready for culture. We have realized, though, that some capsules opened during the shipment, so we might update the flyer sometime soon to clarify better the right stage for collecting samples. In a future update we will include some extra information on how to send your samples to ensure that the spores stay viable (we have learned a few things about how to maximize success).

We sterilize the spores in a 1% bleach solution in water to make sure that no bacteria or fungi are present, and then we inoculate Petri dishes with those spores. We keep them like this until they reach enough development to be transferred to soil.

From your backyard to our labs!

Each sample contains a reference number so we can track back the information of that strain to your individual collection. After some time growing on Petri dishes, we transfer the moss tissue to soil containers, where they grow up to completion of their life cycle. At different stages of this process we use the tissue for genomic studies, flow cytometry, or generation of polyploid mutants. We also ship samples of these cultures among the different institutions of the project (From the University of Connecticut to Augustana College and Texas Tech).

Containers with Physcomitrium cultures on soil. In these closed containers they continue their development and they can be used for the different research purposes.

How are we doing so far? We have about 110 different active Physcomitrium strains, including those that we have received thanks to the PhyscoHunt contributors. This has been definitely very helpful and we hope you also feel excited to see your local goblet mosses being part of our project. In a future update we will be more specific about our objectives and priority areas for the 2020 season. Stay tuned!

Hello to all Physcohunters!

Many of you are already experts spotting those goblet mosses out there. However, they are often found when the capsules are still too young and green to be collected for our project. This is ok if you can record the location and return a few days later, but, what if you don't plan to return to that location? Is this a missed opportunity? Worry no more! This scenario is ideal to learn how to grow mosses in a terrarium.

BASIC MOSS TERRARIA

A simple bryophyte terrarium I kept for a few months

If you are interested in mosses and other bryophytes, you might like to know that they can be kept indoors without too much maintenance. The basics for a bryophyte terrarium is a closed transparent container that can hold a moist (saturated) atmosphere. It can be a fancy glass bell like the one I found around my lab, a jar, a plastic container, etc. In fact, this is basically what we do in our labs of Connecticut and Illinois to keep and propagate the Physcomitrium cultures that you send us.

The moist soil serves as a reservoir of water to keep hydrated the mosses. You can place this container virtually anywhere in your house, but many moss species in these terraria will do well in well lit conditions but protected from direct sunlight. Some condensation will likely appear inside the container, and that's ok (however, read below for the particular case of Physcomitrium). You can always open for a few hours the container if you want to reduce condensation as long as you keep inside enough humidity to keep the mosses hydrated.

These basic terraria can last for a decent amount of time (many weeks). However, often the new growth of mosses inside will not look too pretty and your initial arrangement may not look too well after a while. You may consider to replace them at that point.

Bryophytes are valuable biodiversity assets in many ecosystems and we will never advocate for heavy collecting in the wild just for aesthetic purposes. However, many common mosses that you can find in disturbed and populated areas, such as your backyard, sidewalks, etc, will grow well in a terrarium and will make more accessible its interesting life cycle. Since goblet mosses are indeed one of these very common and ubiquitous bryophytes , they are ideal for this purpose!

MATURING GOBLET MOSS FOR THE PHYSCOHUNT

Ok, so you found some green goblet moss in your weekend trip. It is still too young to be sent to the PhyscoHunt guys, but you don't want to miss this opportunity, so, what to do?

First, report the observation using iNat. Business as usual. And then, collect the green sample and prepare a mini-terrarium for a few days, Just enough time to let the capsules turn brown. This can be done in ANY sort of closed transparent container. Literally.

Examples of not-so-fancy terrarium containers in which I have matured goblet moss in the past. Even one of those zip-lock plastic bags will do the trick.

Make sure you include enough moist soil (or maybe a moist piece of towel paper) as a reservoir of water. Keep an eye on your moss during the next days, and take it out of the mini-terrarium to dry out completely once the capsules look brown, as explained in our previous post. There is, however, an important consideration: excess of humidity may make the capsules moldy. For some reason, during this stage of the development the goblet moss sporophytes are very vulnerable to fungi. This makes sense: Physcomitrium are ephemeral mosses, meaning that unlike perennial mosses (those that remain present in a spot during several seasons) they complete their life cycle in a relatively short period of time, and then they decay. In their natural environment, these mosses are used to a drop in humidity towards the last stage of their development.

What to do? Monitor your mini-terrarium closely: the leafy part of the moss should remain fresh and hydrated, but you should not see too much condensation. Instead of closing it completely, leave the container slightly open and monitor that the moss does not dry completely until the capsules turn brown.

Do you have questions for us?

Have you ever tried to keep a moss terrarium?

Feel free to make your comments below

Hello everybody!

The past weeks have brought a significant activity in the project. We have a lot of Physcomitrium popping in many states of the Southern US, from Texas to the Carolinas, and we have reached the amazing number of 37 project members, thank you for your support!

With this first "blooms" of goblet moss we are also finding the first challenges on how to identify them in the field, when to collect them, etc. Today I will try to help a little with this, please, feel free to comment or email me any questions.

Many of the recent observations on iNat show very nice colonies of Physcomitrium in their early stages, with the capsules expanding, like the image in the banner of the group:

Young Physcomitrium colony

Or this one from @adiamond:

Another young Physcomitrium colony

Note the upright stalks and the pear-shaped capsules with their calyptras. Spore production (due to the biological process of meiosis) is on fire at this stage, but the young spores still need to mature and to be covered with sporopollenin, the substance that will make them extremely resistant out there.

At this stage it is very easy to misidentify young Funaria colonies, the bonfire moss, and take them for goblet moss (Physcomitrium). I have already seen a few of these, and the automatic ID app of iNaturalist also has some problems identifying them correctly. Take, for example, this picture submitted by Helen Hamilton via email.

A young colony of Funaria

The calyptra covering the capsule is very similar, and at first the stalks are short, so it is virtually impossible to tell them apart from goblet moss. However, very soon the Funaria stalks grow tall and the capsule seems almost hanging. The "beak" (rostrum) of the calyptra is also relatively longer. These images remind me of swans, with a long neck and the beaked head almost looking downwards.

I hope this helps a little identifying the goblet moss. Now, another important issue is WHEN to collect them. Remember that we will be extremely thankful if you want to take your participation one step further and send us actual specimens. However, the samples from the previous images are not ready to be collected, the spores are too young. A colony ready to be sampled and dried out will look more like those of these observations by kdwhitbey and johnjschenk

Mature Physcomitrium colonies

A closer look to these samples may reveal a situation like this one, a zoomed in capture of the observation from ash2016.

There are capsules in several stages of development here, some of them even completely open, but a majority show a healthy toasted color and the lid still in place. This is exactly the right moment to collect them. as explained in the training guidelines.

As usual, we are happy to help you with your questions.

In a future post I will share some ideas to allow the samples mature indoors if you can't return later to a location where they are green at the moment.

Happy PhyscoHunt!

Rafa

Greetings to all Physcomitrium enthusiasts!

As the days become longer again in the northern hemisphere, many regions with mild winters will begin to see goblet moss in the most unexpected places. If you are a member of this group and are lucky enough to live in the southern United States, Mexico, or the Mediterranean Region, chances are that they are already becoming visible. Many herbarium records of states such as Florida, or from the southern regions of Spain were collected late in January, so we can consider that the season is on!

I remind you that in addition to your observations we would be extremely helpful if you decide to collaborate with our research project preparing some samples for us to culture. It's easy and fun! You have all the training you will need here and we will be more than happy to answer any question. Our labs and greenhouse are ready to begin culturing your mosses!

Hello everyone!

I am very happy to see that one week after the official start of the project there are already some new members here. Welcome, and thank you for your interest. I hope that this project becomes more than a simple aggregation of Physcomitrium records. Ideally this will be a hub to share comments and to give you feedback on your findings. We are very excited to make this link between our research project and naturalists interested in mosses, so feel free to make comments and ask questions anytime.

You probably already know that goblet mosses are usually seen during the spring, and that the colonies popping up during the fall are outliers. Therefore, although we will be busy next spring, we are very interested in the fall populations due to their rarity and unpredictability. We have found herbarium specimens collected in October and November (two years ago there was an October burst of P. pyriforme here in NW Illinois), and even during the winter at lower latitudes. We are not sure about to what extent these populations will complete the life cycle in the fall, and how frequently (if that happens at all) they overwinter. Your reports will be crucial, so keep your eyes open (especially if you live in Mexico, South USA or the Mediterranean Region).

Best

Rafa

PhyscoHunt is the citizen science initiative of a research project funded by the National Science Foundation. We are using Physcomitrium mosses to learn about genome duplication in plants. For that purpose we are culturing strains from this genus growing in North America and Europe, but we have many regions with no representation and we thought that many naturalists might be able and willing to provide data and specimens.

We are using this project on iNaturalist as a hub to share observations and have a space for discussion and feedback. Please, do not hesitate to contact any of the administrators if you have questions.

We have tried to make easy your participation. Our training document will get you ready for action.

Learn more about the project here, and help us disseminating the initiative on twitter with #PhyscoHunt.

PhyscoHunt is funded by the NSF grants (DEB-1753673, 1753800, and 1753811): Diversity of Physcomitrium pyriforme in North America and Europe: significance of autopolyploidy within a phylogenomic and experimental framework. A collaborative project shared among the University of Connecticut, Texas Tech. University, and Augustana College.