New Moss Gardening Book

A new book about moss gardening is out! The Secret Lives of Mosses: A Comprehensive Guide for Gardeners by Stephanie Stuber. The book is available in a variety of digital formats and in paperback. Stephanie recently finished her Master's degree in Public Garden Leadership at Cornell University and is now working as a Curatorial Fellow at the Arnold Arboretum in Boston, Massachusetts.

Overall I think that is is a good book for people interested in integrating mosses into their home garden and learning more about moss biology. She covers the science, culturing, identification, curation, and interpretation of mosses. Stephanie does a nice job introducing readers to the life cycle and a variety of features that are useful for moss identification. Her habit images are vibrant and helpful, however, the photos of microscopic features are not the best quality and the details are difficult to see. The book includes descriptions of 12 common taxa with pronunciations for each genus, which is nice for folks new to moss scientific names. In the section on culturing, Stephanie highlights a variety of ecological components to think about when planting mosses, including light, moisture, and substrate, as well as more instructional topics such as transplanting, companion plants, and maintenance. The sections on curation and interpretation are more helpful for those working at a public garden rather than the at-home gardener, but it is a nice glimpse behind the scenes of a working botanical garden.

It is apparent that Stephanie is well read and knowledgeable about mosses, but I wish that the text would have included more citations to point the reader to the books she read to gain this expertise. She does cite a study that "...documented that beds of moss over soil provide favorable condition(s) for tree growth in the forest and that the removal of them adversely affects the succession of trees (Thieret 1956)." My general knowledge also is that mosses can serve as a moist nursery for seed germination, but having a scientific study that actually demonstrates and supports this idea is even better. I had not heard of Thieret before and will definitely check out his paper to see the details of the study.

A word of caution, the digital editions of this book are reader program specific. I bought a PDF of the book and missed the note that it will only open in the program Adobe Digital Editions. This file will not open in either Adobe Reader or Adobe Acrobat Professional. I know that digital formats for books are becoming more and more common, but I am suspect of the longevity of files that only open in one specialized program. I plan on studying mosses for a long time and I would like to be able to read and refer to Stephanie's book for the next 50 years. I am pretty sure that computers will continue to be able to access regular PDF files, but will this specific Adobe Digital Edition program still be around so that I can open up this program-specific file? I would have really liked the option to purchase a regular PDF so that the longevity of my access would be more likely. Maybe I will just buy the paperbook version too. I am pretty sure I will still be able to open and read a hard copy years into the future. 

DonorsChoose Science Blogger Challenge

This is my first year competing in the Science Blogger Challenge. The challenge: Compete against other science bloggers to raise money for science supplies for students.

At DonorsChoose.org, teachers request donations for supplies to implement a particular project in their classroom. Then people like you or I make donations of a little or a lot to fund their supplies and make the project happen. Crowd-sourcing in action! 

There are hundreds of great projects to choose from on the site. I am especially excited about the projects that use plants! They range from science experiments that examine plant pigments to starting a garden to make basic observations about how plants grow. I think that plants are a great way to get students excited and interested in science. Botanical education is lacking in many schools and most people think of plants as only the green background where animals live. Instead of knowing that they are unique, diverse, and dynamic organisms in their own right. Connecting students to the natural world through plants is a great way to increase their thinking about and hopefully care for our planet. 

To this end, I have setup a page with a list of projects that Moss Plants and More is sponsoring. Check out the projects on the page and if you find one that resonates with you make a donation! I started the ball rolling with a small donation to each project on my page. Even if you don't make a donation please spread the word via your favorite technology or social media. The contest runs now through Nov 5th. The website for my page is http://www.donorschoose.org/moss-plants-science-donation-page 


My fellow Field of Science Bloggers, we are currently in 8th place. I bet that we can move up in the ranking and raise some money to put awesome science projects into classrooms! Anyone else interested in joining in?

Moss Plants Donation Page

October 2012 Desktop Calendar

The calendar for October is a blend of several different moss species occupying the crevice in a stone. The one in the center is Bryum argenteum, the silver sidewalk moss. As the common name suggests, this moss is regularly found growing in urban areas in between sidewalk tiles. 

I think that the color is really great, but now that I think of it I am not sure how it produces that color. Deposits in the cell walls? Papillae? Are they covered in hairs? Many questions with no answers. Maybe if I have time tomorrow I will look it up. Otherwise it is some great plant beauty to appreciate even without the scientific explanation.

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.

Plants Are Cool, Too!

Check out the second episode of the botanical series Plants Are Cool, Too! In this episode, they find preserved leaves from trees that grew 15 million years ago. My guess is that there were mosses growing on those trees. I wonder if any of them were preserved too? It would be amazing to get ancient moss DNA or just to see what some of the mosses looked like. Unfortunately mosses do not fossilize as well as other plants, so finding some in these deposits would be amazing too!

Check out the video below and spread it around.

Sept 2012 Desktop Calendar

This is leaf of Physcomitrium pyriforme or P. eurystomum. I am not sure which species. It was a preliminary photo that we took for some leaf cell measurements that we will be making this semester. 

If you are interested in downloading this desktop calendar follow the instructions below. 

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 loose 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.

Cool New Cryo SEM

The electron microscopy facility that I work in here at UConn just got a new piece of equipment over the summer and I have some images from it to show off. 

The laboratory now has a cryo-stage for the scanning electron microscope! But let's take a step back in case this type of microscopy is new to you. Basically a scanning electron microscope (SEM) shoots electrons at a sample that is placed in a chamber under high vacuum. The electrons bounce off the sample and enable you to detect an image of the surface that is at a much higher magnification than you can see with a light microscope. The light (dissecting) microscope that I have in the lab magnifies 50-250X, whereas the SEM can magnify up to 200,000X! That is pretty awesome in and of itself, but the cryo-stage adds a whole other level to this equipment. Typically the samples that you look at have to be completely dry before placing them into the vacuum. This is a big issue for biological samples, which can be full of water. There are a number of ways to get rid of the water, but these processes often change the shape of the structures. For some studies this is not a major issue, but for other studies scientists are really trying to see what the plants or animals look like when they are hydrated as they would be when alive. 

Cryo-stage to the rescue! With this equipment a sample can be flash frozen in liquid nitrogen with all of the water in place and then placed into the microscope on the chilled cryo-stage. Then the sample can be viewed with the tissues fully hydrated.

I was out of town when they used some of my moss samples for a test run, so I didn't get to see the equipment in action, but here are some of the images that were taken.

This is a leafy gametophyte stem with a cluster of antheridia at the apex. We are looking down at the top of the stem and there is a second leafy gametophyte lying on its side in the background. The leaves are fully expanded and in an arrangement that you would see when hydrated. If they were dry they would be all folded and curled up on themselves.

Here is the cluster of antheridia and hairs at higher magnification. 

And at an even higher magnification. The hairs located in the antheridia clusters in the Funariaceae are characterized by having a large apical cell, which we can see here is fully hydrated. The filaments covering the hairs are probably fungs or bacteria. These mosses were grown in the laboratory but not in sterile conditions.

Some of the leaves were removed from the gametophyte to make for easier viewing. This image shows the inside of the leaf cells. The outline of the cell walls are visible and it is super cool that we can see the water filling each of the cells.

Congratulations to Dr. Cantino and colleagues on their successful National Science Foundation research grant that funded this new piece of equipment.

Moss Tumbleweeds

I just saw this article about mosses living on glaciers in Iceland and the animals living inside them in the New York Times. These balls of moss (glacier mice) are unattached to the ground and can move around the glacier like tumbleweeds. I knew that mosses grow in extreme habitats and even live in Antarctica, but I had not heard about this type of moss growth form before. Pretty cool, moss tumbleweeds!

Coulson, S. and Midgley, N. 2012. The role of glacier mice in the invertebrate colonisation of glacial surfaces: the moss balls of the Falljökull, Iceland. Polar Biology

Glacier Mosses - Fig. 4 from Coulson and Midgley 2012

Other names for these glacier mice are moss balls and rolling moss. This growth form is advantageous for growing on substrates that are unstable like the surface of a glacier or sand dune. 

For some more reading on this type of moss growth form - 

Shacklette, Hansford T. 1966. Unattached Moss Polsters on Amchitka Island, Alaska. The Bryologist 69: 346-352.

Moss Identification Success

Introducing Jaffueliobryum wrightii! Finally I finished up my moss identifications from my field trip to Missouri and Kansas back in March. This is why I don't do much collecting. My collections tend to sit around for quite a while before identifying them makes it to the top of my list of things to do. And unless I have time for identifying them the mosses are best left growing in the wild. 

So Jaffueliobryum wrightii is in the moss family Grimmiaceae. A telling feature is that the leaves have long, white awns at the tips. Thus, I jumped directly to the Grimmiaceae for my identifying. The genus Jaffueliobryum is usually found on calcareous rocks. This population was growing on sandstone. It doesn't really have a common name, but the genus was named for Félix Jafuell, a clergyman who collected plants in South America. There are only 3 species in North America. One only in Mexico and the other two are widely distributed across the western United States. So once I identified it to Jaffueliobryum there were only two species to choose from. The other species, Jaffueliobryum raui, has keeled leaves (the same idea as the keel on a boat, they look folded or have a ridge down the center), which can be easily seen after making a leaf cross-section. Since this sample did not have keeled leaves, it was Jaffueliobryum wrightii.

It was a really fun plant to identify and I'm glad I got the chance to spend some time with it under the microscope. Now off to the herbarium this sample goes.  

    

Identification and species information in this post is from the Bryophyte Flora of North America.  

Mosses produce Scents that Attract

Photo: Erin Shortlidge, Portland State University

I am a little behind in posting about the moss research that came out in the journal Nature a couple of weeks ago. Researchers found that a moss with separate sexes produce volatile compounds (scents) that can attract microinvertebrates, which in turn increases sexual reproduction.

Todd N. Rosenstiel, Erin E. Shortlidge, Andrea N. Melnychenko, James F. Pankow, & Sarah M. Eppley. Sex-specific volatile compounds influence microarthropod-mediated fertilization of moss. Nature. doi: 10.1038/nature11330

 

For some additional science news coverage of the research check out these articles below.

Science News - I really like this article. The journalist did a nice job of contacting other science experts, some of whom I know, to comment on the research.

New York Times - Pretty brief article, but I was glad to see they covered it. 

News Release from Portland State University - All the details and contacts. Also the title is super catchy.

This research connects to and builds on an earlier study that demonstrated that microarthropods increase fertilization rates in mosses. Now there is good evidence that the mosses are attracting the microarthropods to assist in sperm movement

Cronberg, N., R. Natcheva, and K. Hedlund. 2006. Microarthropods Mediate Sperm Transfer in Mosses Science 313: 1255. 

This research is really changing our thoughts on how we think about sexual reproduction in mosses. Animals help to move the sperm around. The plants produce scents to attract them. And even if they do dry out some sperm can survive desiccation (study below).

Shortlidge, E. E., Rosenstiel, T. N. and Eppley, S. M. 2012. Tolerance to environmental desiccation in moss sperm. New Phytologist 194: 741–750.

Overall I think it is really interesting research to read and think about. 

August 2012 Desktop Calendar

The summer has been in full swing here with science meetings, summer research projects, and manuscripts almost submitted. I have also been gearing up for a large vacation to France. This is the first big one that I have had since I visited Malaysia and Indonesia in 2010. I think that a big vacation needs to be on my calendar every too years.

Speaking of calendars, I dropped the ball on the calendar for July, but here is the August calendar. Ready to go a day in advance! If your first thought was that this is not a moss then you would be correct. The mosses decided to take a August vacation too! Instead the underside of a fern frond from my trip to Malaysia has taken its place. I hope that you have a great vacation month. Take some time to enjoy nature and recharge. Cheers!

If you are interested in downloading this desktop calendar follow the instructions below. 

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 loose 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 > 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.

A Sporophyte Gone Wild

What happens when a moss sporophyte's calyptra does not detach properly? Really odd development! I came across this sporophyte in one of my Funaria hygrometrica cultures recently.

Calyptra Recap: The calyptra is a small cap of gametophyte tissue that covers the moss sporophyte apex during its development. It is necessary for proper capsule and spore formation in moss sporophytes. Studying the calyptra-sporophyte interaction was the focus of my dissertation research. (You can read more about my main findings here. The calyptra has a cuticle. - The calyptra cuticle develops early relative to the sporophyte cuticle.)

So, this really odd development. It looks like the calyptra did not detach from the rest of the leafy gametophyte properly. Usually there is a line of dehiscence at the bottom that allows the calyptra to separate as a distinct cap. In this specimen the calyptra appears to have split open down the side with the sporophyte continuing to grow. As usual, sporophytes without their calyptra on top do not develop a capsule at all and instead produce an obconic-shaped sporophyte.

On this sporophyte, the apical region and seta meristem both appear to have turned brown and died. Also, there is a funny little projection of tissue sticking off the right side of the thickened stalk. (There is a zoomed-in photo below.) I don't think that I have ever seen anything that looks like this on a sporophyte before!

What is it? Is it branching? Maybe. Is it the beginning of a leaf? Probably not. It would be really cool to section it and see what the internal anatomy looks like. Does it have  central strand tissue going out into it? It looks pretty small so probably not. I wonder if I saved this sample in the lab after taking some photos of it so that I can process it for some anatomical study. Either way, I think that it is some pretty cool morphology to think about!

 

On the Left: An close-up of the sporophyte breaking through the side of the not detached-calyptra. On the right: An up-close view of the tissue projecting from the sporophyte.

Conducting Cells in Mosses

I got an email a while back asking about the leptom and hadrom in mosses (sometimes both of these terms are spelled with an added -e at the end). Admittedly I had not heard these two terms before, but I was pretty sure that they referred to the hydroids (water conducting cells) and leptoids (photoshythate/sugar conducting cells) in mosses. Yes, some bryophytes do have specialized cells for conducting either water or sugars through their plant body, however, the walls of these cells are not strengthened by the compound lignin, so they are not termed xylem and phloem.

I headed to my handy reference shelf to look up the definitions of these two terms and here is what I found about the water conducting cells of mosses.

The hadrom is a term for all the of hydroids together in a structure. In mosses hydroid cells are present in the peristomate mosses (those with teeth around the mouth of the capsule) which includes the Bryopsida, the crown group of mosses, and the Polytrichopsida, the hairy-capped mosses. Hydroids are lacking in some of the earliest diverging lineages: including Sphagnaceae, Andreaeaceae, and Andreaobryaceae.
(Paragraph Updated 16 April 2014:  An earlier version of this post incorrectly stated that hydroids are only present in the Bryopsida. However, in Ligrone et al 2000 they state that hydroids are present in the Bryidae. This older name for the group includes both the Bryopsida and the Polytrichopsida and thus has been updated in the paragraph above.)

The leptom (consisting of leptoids) is unique in mosses to the Dawsoniidae and Polytrichidae (the group of mosses that includes Polytrichum, the hairy capped mosses). Other groups of mosses have cells that could be termed 'conducting parenchyma cells', but they are not as specialized as leptoids. 

These terms (leptom and hadrom) were introduced by the German botanist Haberlandt in 1879, which is probably why I hadn't heard of them before.

If you are interested in reading more, this paper has a very thorough and readable discussion of water conducting cells in bryophytes, which I consulted for the above information on hydroids and leptoids.

R Ligrone, J G Duckett, and K S Renzaglia. 2000. Conducting tissues and phyletic relationships of bryophytes. Philos Trans R Soc Lond B Biol Sci. 355: 795–813. 

To give you a visual of these conducting cells, I remembered that I came across some during the course of my dissertation research. Below is a transverse section through the midrib of a gametophyte leaf of Funaria hygrometrica.

The cells with the thickest walls in the middle-center are stereids, which help to support the leaves. Directly above them are two cells that have a 'blown out' appearance. These cells do not have any cytoplasmic contents and have a very thin wall between them. I would interpret these cells as hydroids. Above and slightly to the right of the hydroids is a large cell with intact cellular contents and a large number of pores in one of the cell walls. Thus I think that this is a food conducting cell or conducting parenchyma cell. 

I have blown up the image and added some letters to help orient you to the larger image above. (Key: stereid = s, hydroid = h, food conducting cell = fcc)

It has been a while since I have looked at and interpreted electron micrographs. Well maybe not so long ago. I did a lot of that for my dissertation but the interpretation stage seems like, and was a couple of years ago. Interpreting this micrograph was super fun and tells me that I need to get back to the electron microscopy lab and generate some more images and data to interpret and think about!