Mosses on the Walls

Many species of mosses grow on vertical surfaces. Rock walls, brick walls, trees. Unfortunately mosses on vertical surfaces are pretty scarce here in the central valley of California. Despite the scarcity, I now have some new mosses hanging on my wall at home.

From the Yale Peabody Museum

This is not a wall hanging but is a moss covered dishtowel! I decided to hang it in the kitchen instead of using it as a towel. Now that I see it up on the wall I think it could use a bit of ironing. 

The images on the towel are probably from an old German text illustrating the different parts of the mosses.

Above are sporophytes attached to some leafy gametophytes. But what is the moss species? The light pink and green circle in the middle left is the top of the capsule and looks like a moss in the Polytrichaceae. Nematodontous teeth with an epiphragm. Basically those are teeth around the opening of the capsule attached to a disc that combine to form a salt-shaker dispersal mechanism. However, the gametophyte leaves don't look like Polytrichaceae. The leaves are typically covered in lamellae and are significantly longer than wide. Anyone else have a guess about this species? There wasn't a reference for the images on the towel. It would have been super nerdy and helpful if they had included a citation. 

Some beautiful peristome teeth.
A Dicranum-type on the left and a Bryum-type on the right.

Thanks Rachel for this awesome present! A great combination of my love of mosses and my midwestern abundance of dishtowels!

November 2013 Desktop Calendar

Another lovely moss from our summer hike up Mt. Monadnock in New Hampshire. This is the moss Polytrichum commune. Its common name is the hairy-capped moss, named so for its hairy calyptra. Calyptra are the little caps of maternal gametophyte tissue that cover the top of the young offspring sporophytes. These caps prevent water loss from the apex of the developing plant. Think of it as your mother sending you out the door to play with a fuzzy little cap atop your head. However, this cap is meant to keep your wet hair from drying out rather than to keep out the cold. I like to think of it as a reverse shower cap. A little odd to imagine the human equivalent, but it works well by keeping the top of the mosses moist in the dry air. For more on calyptra, check out this summary about my PhD research studying calyptrae. Happy November!

1 - Single click on the image to open it up in a new window. (If you use the image directly from the blog post you will lose a lot of resolution.)

2 - Right-click (or ctrl-click) on the image, and chose the option that says, "Set as Desktop Background" or "Use as Desktop Picture". The wording may vary.

3 - If the image does not fit your desktop neatly, you may have to adjust the image (Mac: System Preferences - Desktop and Screen Saver - Desktop; Windows: Control Panel - Display - Desktop) and choose "Fill screen" as the display mode of your background image.

September 2013 Desktop Calendar

This image from one of our hikes in South Tahoe last month. We started at the end of a tiny windy road that ran along Fallen Leaf Lake and hiked up to Gilmore Lake. These Polytrichum mosses were growing along the edge of the lake. They make for a very busy image. So busy that it is a little challenging to see the calendar. Hopefully your September is not nearly as busy as this photo!

1 - Single click on the image to open it up in a new window. (If you use the image directly from the blog post you will lose a lot of resolution.)

2 - Right-click (or ctrl-click) on the image, and chose the option that says, "Set as Desktop Background" or "Use as Desktop Picture". The wording may vary.

3 - If the image does not fit your desktop neatly, you may have to adjust the image (Mac: System Preferences - Desktop and Screen Saver - Desktop; Windows: Control Panel - Display - Desktop) and choose "Fill screen" as the display mode of your background image.

An Ecotourism Vacation

The end of the school year has me thinking about summer vacations and I have just added a new location to my vacation wish list. The Cape Horn region of southern Chile and Argentina sounds like an amazing place to visit! The area has high levels of bryophyte diversity and a beautiful landscape of waterways and islands. Unfortunately my summer vacation plans do not include the Cape Horn this year. Instead I have been reading a book all about ecotourism of the miniature forests and imagining myself there. 

Miniature Forests of Cape Horn: Ecotourism with a Hand Lens (2012) by Bernard Goffinet, Ricardo Rozzi, Lily Lewis, William Buck, and Francisca Massardo.

This book makes it easy to imagine you are far away in the Cape Horn. There are many full color photos of the landscape and a up close photos of the plants. They also identify the many species of mosses, liverworts, hornworts, and lichen that live in the Cape Horn region. The book has text in both English and Spanish, as you can tell from the cover. 

For some of the species they describe interesting structures, such as the lamellae on the leaves of the Polytrichaceae.

For others, cool interactions, such as the flies that are attracted to moss capsules and disperse the sticky spores are featured.

Overall I think that it is a great book. I may be a little biased since I know two of the authors quite well (Goffinet was my PhD advisor and Lewis was my labmate at the University of Connecticut). I think that the book is a great outreach tool and I hope that many people will take them up on visiting the area to see the amazing miniature plants. 

November 2012 Desktop Calendar

I was hiking in Hubbard Park in Meriden, CT this past weekend and came across this Polytrichum piliferum. It was growing on some rock at the top of the outcrop near Castle Craig. I thought that the calyptra looked especially fuzzy and luminous in the sunshine. Most likely these sporophytes will over-winter at this spear stage and will complete their development by forming capsules in the spring.

1 - Single click on the image to open it up in a new window. (If you use the image directly from the blog post you will lose a lot of resolution.)

2 - Right-click (or ctrl-click) on the image, and chose the option that says, "Set as Desktop Background" or "Use as Desktop Picture". The wording may vary.

3 - If the image does not fit your desktop neatly, you may have to adjust the image (Mac: System Preferences - Desktop and Screen Saver - Desktop; Windows: Control Panel - Display - Desktop) and choose "Fill screen" as the display mode of your background image.

Any issues or suggestions please let me know. These calendars are an experiment in-progress.

Moss Feet

Did you know that mosses have feet? No joke they do. But they don't use them to walk or run around. And thank goodness, because I am glad that I don't have to go chasing them when I go plant collecting.

Ok, bryophyte feet. At the bottom of the bryophyte sporophyte is the foot. It is the region where the un-branched sporophyte is physically attached to the leafy gametophyte. The foot functions in the transfer of nutrients from the maternal, leafy gametophyte to the sporophyte. These are a couple of good reviews about this region in mosses and across land plants.

Ligrone, R. and Gambardella, R. (1988) The sporophyte-gametophyte junction in bryophytes. Advances in Bryology 3: 225-274. (book)

Ligrone, R., Duckett, J. G. and Renzaglia, K. S. (1993) The gametophyte-sporophyte junction in land plants. Advances in Botanical Research 19: 231-317.

My thinking about bryophyte feet was stimulated by a question from a colleague in my department. They were teaching the students about mosses in the Introductory Biology class and were discussing why in old, mainly brown sporophytes of Polytrichum the foot remains green. Early in development the entire sporophyte is green and photosynthetic. Later in development the capsule and stalk turn brown/red and dry out.

Here are some reasons why I think that the foot may remain green long after the rest is no longer photosynthetic. These are just my hypotheses/ideas. I don't have any data or citations to back them up. (1) It is protected from desiccation by the surrounding leafy gametophyte and thus does not dry out. Resulting in it remaining green and hydrated for longer. AND/OR (2) Since it is involved in nutrient transfer from the leafy gametophyte to the sporophyte, it may remain metabolically active and functioning in nutrient transfer until late in sporophyte development. Being able to function in nutrient transfer would require that this tissue is still alive and maybe also photosynthetic = green.

You can see the foot of a moss sporophyte by gently pulling the sporophyte out of the gametophyte that it is attached to. I honestly only remember trying this on Polytrichum when teaching intro bio. I am definitely going to have to take a look at the feet of other species of mosses to see if they also remain green long after the sporophytes have become brown.

Persistent P's Permeating the Polytrichiaceae

In lab group last week we read an article about the moss family Polytrichiaceae. These are the mosses that have fabulous little lamellae on their leaves. Some species are quite common and can be found in open disturbed edge habitat. They can be recognized by their star-shaped form when viewed from above and they are often one of the largest mosses that you will see in the field.


Bell, Neil E. and Jaakko Hyvönen. 2010. Phylogeny of the moss class Polytrichopsida (BRYOPHYTA): Generic-level structure and incongruent gene trees. Molecular Phylogenetics and Evolution 55: 381-398. 

Species are typically grouped into the larger category of genera based on the morphology of the plants, their physical appearance. Thus all the members of the genus Atrichum (the smooth capped mosses) look similar to each other and the same for other genera such as Polytrichum (the hairy capped moss). Sometimes it ends up that these morphological groupings are confirmed by the DNA sequence data and all the members of the genus did descend from a common ancestor. Other times the DNA data shows that the members are not descended from a recent common ancestor and are instead distantly related. The morphology and the DNA evidence tell a different story. In this study both Polytrichastrum and Oligotrichum are composed of members that are distantly related. The later genus has a distinct geographic pattern with all the northern members being related to each other and all the southern members in the other group. Overall I think that it is pretty cool to explore these morphological hypotheses with DNA data. You never know what there is to be found. 

Another paper on this group of mosses by the same authors.
Bell, Neil E. and Jaakko Hyvönen. 2010 A phylogenetic circumscription of Polytrichastrum (Polytrichaceae): Reassessment of sporophyte morphology supports molecular phylogeny. American Journal of Botany 97: 566-578. 

Lamellae Story Debunked

I have been relaying the science tale of lamellae as snorkels for quite a while now (here and here on this blog) and I recently came across some scientific literature that completely debunks that idea. Honestly I am not sure if I read about the snorkel idea somewhere or if it just emerged as common knowledge from taking classes and reading. Sometimes there are just "factoids" that exist our heads and we may not know where they came from. As a scientist I totally should have been more careful about the source of my information prior to relaying in the public sphere on this blog. Despite this embarrassing misleading information, I would like to offer a correction via this post.

The dilemma is that mosses and other bryophytes typically interact with water and air differently than other plants. Vascular plants have roots and internal plumbing (xylem cells) that move water into their body and they take gasses in via stomata, small openings in the leaf surface. Bryophytes on the other hand do not have roots or xylem cells to move the water, they absorb water directly through their entire plant body. They also do not have stomata on the gametophyte plant and thus take up gasses across their entire plant body, too.

Think of having to both drink and breath through your skin at the same time. The parts that are taking up water can't exchange gasses and the parts exchanging gasses can't take up water. So, what's a bryophyte to do?

Well Polytrichum has solved this dilemma using its lamellae. They are the green filaments of cells (see above) on the upper surface of the leaf. They are not acting as snorkels. Instead they are creating spaces for small pockets of air between the lamellae for gas exchange. The air spaces do not become filled by water due to a waxy cuticle that covers the epidermis and the cells at the tips of the lamellae. In Polytrichum water is acquired via internal conduction through the stem of the leafy gametophyte. This internal plumbing is not very advanced, but you can see some of the small conducting cells in the center of this cross-section through the stem of the leafy gametophyte. This plumbing continues into the leaves. 

So that is a bit about our current level of understanding when it comes to lamellae on Polytrichum leaves. Once again I apologize for any confusion I may have caused. It just goes to show that it is important to cite your sources and to double check the knowledge in your head every once in a while.

The papers that I consulted for writing up this explanation are listed below.

Proctor, MCF. (2005) Why do Polytrichaceae have lamellae? Journal of Bryology 27: 221-229.

Robert J. Thomas, Steve H. Ryder, Mark I. Gardner, Jonathan P. Sheetz and Stephen D. Nichipor. (1996) Photosynthetic Function of Leaf Lamellae in Polytrichum commune. Vol. 99, No. 1, pp. 6-11.

Salt-Shaker Spore Dispersal

Mosses in the Polytrichaceae spread their spores in a really neat way. Shown here are Atrichum sporophytes. Another member of the family that I have blogged about is Polytrichum, which also shares this dispersal mechanism.

Atrichum's manner of spores dispersal has been described as a salt shaker mechanism. And as you can see on the up-close shot below, it is a pretty good analogy. The mouth of the capsule is surrounded by a ring of short, immovable teeth that attach to a disc covering the opening to the capsule. The disc keeps rain from entering the capsule so that the spores do not start to grow before they have exited the capsule. When a breeze or a passing animal jostles the capsule the spores sift out from between the teeth. This mechanism also keeps the spores from coming out in a single mass, which would pretty much defeat the ability of these spores to spread on the wind.

If you are ever out in the woods and see some Artichum (or Polytrichum) sporophytes, give them a tap. You may be rewarded by a poof of spores emanating from the top of the capsule.

Fun Fact: Spores are so small and light that they can disperse very long distances. Researchers carried out a study (I am not sure of the reference off the top of my head, but I will check.) where they attached sticky microscope slides to the wings of a plane that flew high into the air. What do you know, they found moss spores all the way up in the the jet-stream. Pretty cool that they are able to travel that far up and then far away!

Moss Stickers

I was cleaning out my office drawers and came across a mossy item that I had not seen in months. (My office drawers tend to become a disaster over the course of the semester.) It was a sticker book made from my moss photos, many of which have been used on this blog. The company that I used is at www.moo.com and is based out of the UK. I had heard about them from somewhere and really liked the idea of making a sticker book. The books come with 16 perforated pages and you can upload a large number of images. I think that I could have had every sticker in the book of a different photo. Instead I picked a set of 12 that I liked, because I knew I would be giving them away. I passed out sheets of these stickers to my labmates and many of them ended up on the fronts of their laboratory notebooks. It wasn't exactly where I had imagined them sticking, but they seem to have enjoyed them. I even have a couple of sheets left! Now I just have to decide where to stick them...

The Stickers shown in the photo from upper left to right: Polytrichum gametophyte stems with fall leaves, Polytrichum stems up close, and Funaria hygrometica. Second Row: Leucobryum mixed with Dicranum, Leucobryum tuft, and Leucobryum upclose. Lower sheet, top row: Anacamptodon capsule, Tetraphis gemmae cups, and Sphagnum. And finally Sphagnum leaf cross section, Tetraphis peristome teeth at the top of the capsule, and Tetraphis gemmae.

Moss at the Kannon Nature Museum

We had a home stay with a Japanese family this past weekend. The family lived in the city of Yokosuka, south of Tokyo. Since the other graduate student and I staying with the same family were both biologists they took us to a local park near their home and to a nature museum.

The park was very nice. We saw a variety of animals: koi, turtles, dragonflies, white-eyed warbler, and a variety of other cool insects. My favorite were these shiny little insects!

There were a number of mosses hiding under bushes and between blades of grass. However as we were walking along my host mother translated one of the signs on the side of the path and it read dangerous snake. I am not a fan of snakes, especially the dangerous kind. Hence there is no picture of the mosses from the park, because after reading that sign I stopped poking around in the brush and stuck to the path.

After visiting the park we were off to the Kannon Nature Museum it sit directly on the coast of Tokyo Bay. The day we visited it was quite foggy over the bay obscuring our view. The museum itself was fantastic and much more than I expected. They had vases full of a large number of native plants that were collected from the area and on display. Of course being near the ocean there were all manner of pickled sea creatures, including fish, mollusks, urchins and octopus.

Unfortunately the most poorly curated display was that of the mosses and ferns. There was a small shelf, pictured here that had about six different types of ferns. Most of them were labeled with their Japanese names and some with their scientific names. However the poor lonely mosses on the bottom shelf did not have any labels at all. Poor things. The two containers on the end are filled with Polytrichum and the middle container has some Dicranum and Polytrichum. I know that I saw more types of mosses in the area than just these two. What happened? No love for the mosses?

I do not have a key or guide to the mosses of Japan, so I am not sure what species in particular they had on display. Many species of moss have world wide distributions, so these could be the same species as those we have in Connecticut.

My plan is to talk to the researchers here in Dr. Hasebe's Lab to find out if they know of an English guide to the mosses. I learned a little Japanese before coming, but I do not think that it is nearly enough to use a field guide.

I am off to explore the town of Okazaki this weekend. As of now my main transportation is on foot, but I have a map and I might give the bus system a try. I really wish that I brought my GPS unit or a compass just in case I get lost. Wish me luck!

Off to Study Mosses in Japan

Well this is my last day in Connecticut before heading off to Japan tomorrow. My laundry is done, the lab is tidy, and some of my fabulous fellow graduate students will be taking care of my mosses here in Connecticut while I am gone. I still have a full day ahead of me with packing and cleaning my apartment, but the anxiety about the trip is starting to fade away and I am finally getting excited about the whole adventure.

One of the items that is quite important when meeting people professionally in Japan are business cards. Thy are called meishi in Japan. There is a formal method of meishi exchange that includes bowing. Here is a link to the entire story regarding meishi exchange. Hopefully I will not completely botch the exchange process and I can avoid embarassment.

Of course the business cards that I ordered got tied up in the printing and shipping process and will not arrive before I leave. Hopefully I will be able to have them sent to me so that I can use them while I am there.

I have posted versions of my business card in english and the one the my Japanese research advisor translated into english. The translation is pretty rough. Looking up Japanese characters is not easy. It says Connecticut University Ecology and Evolutionary Biology on the first line. Doctoral University student on the second line. The third line is my name. The prevaling comment that I have gotten is that it is pretty fun that my name in Japanese has two smiley faces. : ) The following lines are my contact information at the National Institute for Basic Biology.

On the at home front, the moss walk this past Saturday went well. We had six participants who came on the walk. We didn't walk very far, which is usually the case when looking at mosses, but everyone had a good time. Since everyone on the walk was new to mosses I introduced several of the common genera that can be found in Connecticut.

Atrichum Hypnum Leucobryum Polytrichum Plagiomnium Sphagnum

Well that is all for now and I will next be posting from Japan. Wish me luck.

The Common Names of Atrichum

Mosses in the genus Atrichum have a couple of common names, as many plants do. One name is the smoothcap moss. As I mentioned in last week's post, this name describes the lack of hairs on the calyptra of Atrichum, which is contrast to the hairy calyptra of Polytrichum (the hairy capped moss).

The other common name for Atrichum mosses is the catherinea moss. Originally the genus name for this moss was Catherinea. This name was given to these mosses in honor of Catherine II, who was the Empress of Russia from 1762 to 1796. Historically botanists named plants in honor of their wealthy patrons who funded their research. This genus was named by the German botanist Jakob Friedrich Ehrhart. He was a student of Linnaeus, the famous scientist who came up with the system of binomial nomenclature (Genus species).

Mosses as the Ultimate House Plant

As many of you know, house plants require regular watering and attention. I usually water mine once a week unless it is quite hot. If I forget to water them they start to wilt and with extreme lack of attention on my part they shrivel and die, which has happened on occasion.

Most flowering plants are drought tolerant. Meaning, they can handle times with low amounts of water, but mostly they try to avoid drying out completely. They have a number of cool features that keep water from escaping their bodies. Bark and a thick waxy cuticle layer keeps water in the stems and leaves, respectively. They can also control how open or closed their stomata are to regulate the amount of water that escapes from these pores. And an extensive root system keeps a constant stream of water flowing into the plant.

Mosses have a completely different system than the one I just described. Instead of having features that keep them from drying out, they are ready and willing to dry out at a moments notice. They are termed dessication tolerant. They have the ability to loose ~100% of the water in their cells and then when watered they come back to life. It is as though they are able to go into periods of suspended animation while they wait for the water to return.

Most flowering plants are not dessication tolerant. If they loose 70-100% of the water from their cells they are toast (aka. dry and dead) and will not recover. However having a moss as a house plant would be a great solution for those of us who sometimes forget to water the plants before leaving for vacation. They could dry out completely for a number of days and happily return to life when watered again. Thus I would consider them the ultimate resilient house plant!

Shown here is a photo of a Polytrichum that is all dried up and crispy, patiently waiting for some moisture to come its way.

This post was stimulated by an article that I am currently reading. See below the fold for the reference, which includes more detailed information on dessication tolerance in mosses.

Proctor, M. C. F., M. J. Oliver, A. J. Wood, P. Alpert, L. R. Stark, N. L. Cleavitt, and B. D. Mishler. 2007. Dessication-tolerance in bryophytes: a review. The Bryologist 110(4):595-621.

The Hairy Cap

Based on a request from last week, I have posted a photo of the hairy cap of Polytrichum commune. The technical name for this cap or hood is a calyptra (plural=calyptrae). It typically sits atop the moss sporophyte and covers the capsule. This highly hairy hood (try saying that 3 times fast) is a characteristic that is shared by members of the genus Polytrichum. Calyptrae may be found year round, but are most prevalent during the late summer and early fall in Polytrichum commune. The stalk, capsule and calyptra are attached atop the leafy portion of the moss. Check out the post from October 8th and imagine the structures shown today growing out of the apex of the leafy plant. If you have located the hairy calyptra you have found a Polytrichum.

Moss Snorkels

WARNING: This information is inaccutate. Please see this more recent post for additional information.

Mosses along with all other plants need water, sunlight and air to live. However mosses don't have roots, which is the usual way that plants move water into their bodies. Instead they take up water from the environment through their outer layer of cells. They also exchange gases through this layer of cells. This causes a dilemma. Mosses have to drink and breathe through their "skin". Polytrichum commune and its close relatives have come up with a ingenious solution to this problem. They have snorkels. Okay they are not technically called snorkels, they are called lamellae, but that is what I like to refer to them as when I explain how they work. When the moss leaves are wet their entire surface is covered by a film of water. Gas exchange cannot happen through the water, but the snorkels stick out above the water and are dry at the tips to allow for gas exchange. The image that I posted is a section through a Polytrichum commune leaf, with the top side up and the bottom side down. The shiny white cells make up the thickened portion of the leaf and each green filaments of cells is a snorkel. Then wet, the spaces between the snorkels are flooded with water and the upper-most snorkel cell is exposed to the air. If you zoom in on this picture you may be able to see that the upper-most snorkel cells have a notch or divot in them. This is a microscopic clue that tells us this leaf is definitely from Polytrichum commune.

Polytrichum commune from another angle

Mugshot of a Moss

Based on a comment from last week I decided to introduce Polytrichum commune, the common hair capped moss (hairy cap not pictured). This species can be found in wet areas of yards or meadows across North America and beyond. I discovered this individual growing in a wet spot next to a picnic shelter. This species is easily recognized by its stout appearance and star shaped spray of leaves, which can be seen when viewed from above. The individuals are pretty large as far as mosses go. The one pictured here is about 4cm tall and they can reach heights of 30cm or more. However those that I have seen around Connecticut are usually not skyscraper sized and range from 4 to 10cm. This is a species that I run across nearly every time I am out looking at mosses.