July 2015 Desktop Calendar

Some lovely liverworts from Chile to grace your desktop this month!

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 Image as Desktop Picture" or "Save Image As...". The wording may vary. (If saving the image to your computer is the only option, then locate it on your computer and choose the "Set as Desktop Background" or "Use Image as Desktop Picture" option from there.)

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.

The Bryophytes on the Cover

The front cover of Elizabeth Gilbert's new novel The Signature of All Things features some lovely bryophyte paintings. They are from the 1905 edition of the German encyclopedia Meyers Konversations-Lexikon. I have not had the pleasure of perusing this encyclopedia, but I do have fond memories of an English version of encyclopedia Britannica. My parents bought a set when I was in elementary school. Black and red cover, crisp glossy pages. Ah, memories. Can you tell I am a bit of a bibliophile? For those of you who have not enjoyed a hardbound encyclopedia set, they were the precursor to google and wikipedia. Want to know something about a fast animal, far-a-way country, historic event, or odd fruit? As my dad would always say, "Go check the encyclopedia." It provided tons of information to answer my pressing questions and constant need to know. Sometimes my sister and I would just sit down with a volume and flip through pages, reading about interesting topics for fun. Did I mention that I grew up in rural Indiana and there weren't a lot of entertainment options?  


Back to the bryophytes of the beautiful image on the cover of The Signature of All Things. In terms of bryophyte identification, there are some complex thalloid liverworts in front with tall antheridiophores and archegoniophores springing up from the ribbons below. Antheridiophores are the male reproductive structures that produce sperm; archegoniophores are the female reproductive structures that make eggs.  On either edge of the cover are mosses with sporophyte capsules elevated on tall stalks. They are most definitely members of the Splachnaceae, the dung moss family. I love saying that name (SP-laCK!-n-ace-a-ee). It has a very dung-y ring to the name! My best guess on a species level identification is Splachnum luteum.  The common names for members of this genus are really great. They include umbrella moss and petticoat moss, which describe the shape of the capsules. I think that petticoat moss is especially fitting for the cover of a book set in Victorian times, about a woman who most likely wore petticoats. 

October 2013 Desktop Calendar

Pictured here are a few mosses in yellow-green that are surrounded by some complex thalloid liverworts for your October desktop. These are from our hike to the Stebbins Cold Canyon Reserve this past spring. The weather is finally starting to cool down here in the central valley and I am hoping that we will get out for a few more hikes while the weather is lovely and comfortable. Happy botanizing!

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.

Rare Mosses and Liverworts of England

It has been a full week with little time for me to work up my own blog post. Instead I encourage you to check out a post over on the IAB blog by a bryological colleague, Juan Carlos Villarreal. It is a book review of a new text focusing on rare mosses and liverworts of England. He gives you the highlights of the book and includes the details of one rare moss species Telaranea murphyae Paton. Enjoy!

Click here for a link to the IAB blog.

Relationships between the Three Groups of Bryophytes

I got an email this week from a colleague about the state of the relationships among the three groups of bryophytes: Mosses,  Liverworts, and Hornworts.

The first questions to consider - Are they three separate lineages? OR One monophyletic lineage?

If they are three separate lineages, what order should they be placed in relative to tracheophytes (plants that have tracheids, a special type of xylem)?

Well it all depends on which data are used.

Data from sperm ultrastructure (Garbary et al. 1993) and DNA data from entire chloroplast genomes (Nishiyama et al. 2003) points to the three groups being part of a monophyletic lineage, as in the diagram on the right.

However all the other studies that I can think of support these three lineages as independent and as a grade diverging prior to the evolution of the tracheophytes.

This phylogenetic relationship was proposed based on morphology, physiology, and biochemistry data (Mishler & Churchill 1984). Then subsequently supported by molecular sequence data (Mishler et al. 1994).

 

Another alternative hypothesis was supported by sporophyte morphological data (Garbary & Renzaglia 1998) and cox3 mitochondrial sequence data (Malek et al. 1996).

So, I think that this could be presented to students as an active scientific example of different data giving conflicting signals. Often science is much messier than we explain to students. They could be presented with multiple alternative hypotheses for these relationships and have to discuss the different scenarios or perhaps the different types of data used for each. 

However, if I only wanted to present one phylogenetic relationship to my students I would go with this one, below. This relationship is supported by Qui et al. (2006), which uses molecular sequence data from the chloroplast, mitochondria and nucleus on over 100 taxa. Others may disagree, but this is the phylogeny that I would recommend using as our most current hypothesis for teaching students about relationships among the bryophytes.

References

Garbary, D. J., K. S. Renzaglia & J. G. Duckett. 1993. The phylogeny of land plants: A cladistic analysis based on male gametogenesis. Plant Systematics and Evolution 188: 237-269.

Garbary, D. J. & K. S. Renzaglia. 1998. Bryophyte phylogeny and the evolution of land plants: Evidence from development and ultrastructure. Pp. 45-63 in J. W. Bates, N. W. Ashton & J. G. Duckett (Editors), Bryology for the Twenty-first Century. Maney Publishing, Leeds.

Kenrick, P. & P. R. Crane. 1997. The Origin and Early Diversification of Land Plants. Smithsonian Institution Press, Washington, D.C.

Malek, O., K. Lättig, R. Hiesel, A. Brennicke & V. Knoop. 1996. RNA editing in bryophytes and a molecular phylogeny of land plants. The European Molecular Biology Organization Journal 15: 1403-1411.

Mishler, B. D. & S. P. Churchill. 1984. A cladistic approach to the phylogeny of "bryophytes." Brittonia 36:406-424.

Mishler, B. D., L. A. Lewis, M. A. Buchheim, K. S. Renzaglia, D. L. Garbary, C. F. Delwiche, F. W. Zechman, T. S. Kantz & R. L. Chapman. 1994. Phylogenetic relationships of the “green algae” and “bryophytes”. Annals of the Missouri Botanical Garden 81: 451-483.

Nishiyama, T., P. G. Wolf, M. Kughita, R. B. Sinclair, M. Sugita, C. Sugiura, T. Wakasugi, K. Yamada, K. Yoshinaga, K. Yamaguchi, K. Euda & M. Hasebe. 2004. Chloroplast phylogeny indicates that bryophytes are monophyletic. Molecular Biology and Evolution 21: 1813-1819.

Qiu, Y.-L., L. Li, B. Wang, Z. Chen, V. Knoop, M. Groth-Malonek, O. Dombrovska, J. Lee, L. Kent, J. Rest, G. F. Estabrook, T. A. Hendry, D. W. Taylor, C. M. Testa, M. Ambros, B. Crandall-Stotler, R. J. Duff, M. Stech, W. Frey, D. Quandt & C. C. Davis. 2006. The deepest divergences in land plants inferred from phylogenomic evidence. Proceedings of the National Academy of Sciences of the USA 103: 15511-15516.

My Bryology Bookshelf - V

Another book that I picked up recently was a great book of fabulous images from Bill and Nancy Malcolm, entitled The Forest Carpet. This book is from the authors of the spectacular bryophyte glossary. They cover all three lineages of bryophytes (liverworts, mosses and hornworts), one lineage of ferns, a couple of fern allies (aka. fern friends), and lichens. The images are large, filling the pages of this coffee-table sized book. Each image comes with an informative caption, identifying the specific species pictured and notes the magnification. There are photos of the plants growing in their particular habitat, closeups of the exterior of the plants, and some sections showing the interior arrangements of the cells.

The goal of this book is to make people aware of the smaller organisms that make up the green background that covers the forest floor like a carpet in New Zealand, hence the title. I think that this book does a great job of immersing you into this miniature world!

My Bryology Bookshelf - III

Mosses With A Hand Lens by A. J. Grout 

Third Edition - 1924

A Popular Guide to the Common or Conspicuous Mosses and Liverworts of the North-Eastern United States

In my search for a field guide to the mosses of New England, I came across this book at my university library. I then purchased my own copy to add to my reference shelf. You can check out the entire book here online at GoogleBooks.

Some great aspects of this book are that it is meant to be used with a hand lens. Other books require either a dissecting or compound microscope. The initial dichotomous key is a manageable length with 25 couplets. Then it spits into Acrocarpous and Pleurocarpous mosses that then have a 36 and 14 couplet key respectively. The line drawings are really well done and are quite informative for species identification. The photographs are ok, especially considering they are from 1924, but are pretty grainy and black & white. The diagrams for the liverworts are typically much smaller and with less detail. This may show a bias of the author toward the mosses.

Since the book is quite old some of the names of the genera are out of date. But it is interesting historically to see how the scientific names have changed from then to now.

Catharinea is now Atrichum

Webera is now Diphyscium

Georgia is now Tetraphis

Another interesting finding in this book is that hornworts are described as a specific type of liverwort. They are classified in the family Anthocerotaceae, The Horned Liverworts. Currently the hornworts are classified as a distinct lineage separate from the liverworts. Thus there are three main groups of Bryophytes; Mosses, Liverworts and Hornworts. I am not sure when hornworts were moved to their own lineage. Sometime between 1924 and now? This is a question for my lab-mate Juan Carlos. I will let you know what he says when I see him tomorrow.   
 

Sporophytes of the Liverwort Aneura

 A few weeks back I took these photos of some liverworts in the genus Aneura. They are of the diploid sporophytes (two sets of chromosomes per cell). At maturity the ball shaped capsule is rapidly elevated on a thin, thread-like stalk. The capsule opens via four vertical sits to expose and disperse the spores within.

 When the capsule is immature and before the stalk has elongated the sporophytes look like these two images below. The capsules are the darkened areas at the tips.

 

An interesting aspect is that the stalk elongates quickly. Unlike mosses the stalk of the liverwort sporophyte does not become longer from cell divisions. It becomes longer by all the cells in the stalk expanding and elongating by increasing the liquid inside of their cells. That is why the cells of the stalk are clear. They are stretched very thin. Keep your eyes peeled for this type of sporophyte. This morphology is a key feature for identifying a liverwort.

Takakia

You probably have not heard of this moss before. It it pretty rare and I actually don't know anyone who has seen them in the wild. There are only two species in the genus (Takakia ceratophylla and T. lepidozioides). The genus is native to western North America and a few locations in Asia. 

This moss has an interesting naming history. It was originally discovered with only green, photosynthetic gametophytes. As you can see from the photo at left the leaves are deeply lobed and filamentous. Initially, the gametophyte was identified and named in the liverwort genus, Lepidozia. It wasn't until almost 100 years later that Takakia was found with sporophytes. The sporophytes have a persistent and tough seta/stalk with a capsule that opens via a single curved slit. If it was really a liverwort the stalk would be thin, translucent and ephemeral with a capsule that opens by 4 longitudinal slits. Once the sporophytes were found these species were moved into the genus Takakia and they have been hereafter identified as mosses.

Pretty amazing that it took that long for scientists to discover the sporophytes and then to figure out that they are really mosses.

   

New Bryophyte Guide

I think that there is really a void when it comes to bryophyte field guides for amateurs. I have sent emails to both the Peterson's Field Guide company and the Finder guides suggesting that a guide to the moss genera of North America is desperately needed. Unfortunately there was no reply from either company. I guess they don't think that there is a market for this type of guide. I think that there is, considering that I am asked about what field guide I would recommend quite often.

The first guide that I purchased was Conrad and Redfearn's "How to know the mosses and liverworts". This guide is ok, but the dichotomous key at the beginning is really long and painful. You have to really want to learn about mosses to pull the information that you desire out of this book. Also some of the characteristics they have you look for are microscopic and really cannot be seen with a 10X handlens.

An announcement came out on Bryonet a while back about a new bryophyte guide. It is entitled "A Trailside Guide to Mosses and Liverworts of the Cherokee National Forest" by Paul G. Davison with contributions from Mark J. Pistrang. If you have never visited the Cherokee National Forest, it is a fabulous place. I carried out some of my undergraduate research there and participated in the All Taxa Biodiversity Inventory in the Smoky Mountains. Fortunately many of the genera in this area overlap with other eastern deciduous forest regions of the United States, and thus could be used outside of the region.

I have purchased a copy and I think that this book is great. There are multiple color photographs per genus. The text includes a description about the genus; notes on habitat, size, distinguishing characteristics and reproduction; the number of species in the genus that live in the Southern Appalachian Mountains; the distribution of the genus within Eastern North America. The book covers 52 genera and focuses on larger scale photographs. Thus a microscope is not needed, which is critical for making field identifications.

The specific species that are covered may not be found in your area, but I think that identifications of mosses and liverworts to genus are just fine. When I lead moss walks and teach people local plants we only talk about them in terms of the genus identification. Really to identify these plants to species you need a microscope. However there are a lot of genera to be learned with ~12,000 different moss species worldwide.

Click Here to preview or purchase "A Trailside Guide to Mosses and Liverworts of the Cherokee National Forest".

Japanese Marchantia Videos

There are a number of really cool time lapse videos posted online of Marchantia liverworts. The text is all in Japanese, but the videos are well worth watching. A few of them are self-explanatory, while others are a little abstract if you have not looked at liverworts too closely. A link to the webpage with the videos is here.

I have watched the videos and here is my interpretation/summary of what they are showing.

Row 1

Left: A Marchantia plant is shown growing. This is a great example of flabellate dichotomous branching. The apex divides into two (dichotomous) branches that are equal in size and it occurs in a fan-like (flabellate) shape, all in a single flattened plane.
Right: Watch gemmae grow inside of a gemmae cup. Gemmae are small discs of plant tissue. They are located inside a splash cup. When raindrops fall into the cup they dislodge the gemmae and splash them out onto the soil. One gemmae can grow into an entirely new Marchantia plant. This is a from of asexual reproduction.

Row 2 - All about sperm

Left: A drop of water is added to the surface of an antheridiophore. This is an umbrella shaped structure that houses the antheridia, the organs that produce sperm. When the water is added some cloudy areas appear in the liquid.
Middle: This is a zoomed in shot of the previous video. Sperm are being released from a pore in the surface of the antheridiophore. The antheridia are located in cavities below the surface of the plant.
Right: Even more zoomed in. Aren't microscopes fabulous! Here you can see the flagellated sperm swimming in a twirly, spiral dance.

My summaries of Rows 3 & 4 are below the fold.

Row 3 - More sperm and closer to fertilization

Left: Sperm are shown swimming toward the neck of an archegonium, the organ that produces and contains a single egg.
Right: Then the sperm are shown swimming into the neck of the archegonium toward the egg. After fertilization a sporophyte (2n, diploid) is produced.

Row 4

Left: These umbrella-shaped structures growing out of the thallus are archegoniaphores. They house the archegonia, the organs that produce and contain eggs.
Middle: Unfortunately the link to this video does not work. The image is of an archegoniaphore whose archegonia have undergone fertilization and sporophytes have been produced. The yellow powder coming out of the archegoniaphores is spores.
Right: This video shows spores being released from the sporophytes on the archegoniaphores. The umbrella-tops of the archegoniaphores have flipped up, as though they were blown inside out in a strong wind. All of the particles blowing around in the breeze are spores. Each of these spores can land and grow into an entire new Marchantia plant.

Airborne Sperm Dispersal

Both bryophytes and ferns have reproductive systems with flagellated, motile sperm. In order for sexual reproduction (fertilization) to occur water is needed for the sperm to swim to the egg. This presents a challenge for these plants; sperm can only swim so far and what happens when there is not enough water.

Some species of liverworts have devised an interesting strategy. They explosively disperse their sperms into the air! Researchers in Japan recently published a research paper that includes documentation of the distance the airborne sperms disperse and a video of the dispersal. This phenomenon has been known to occur since the early 1900's, however little attention had been given to it. The stimulus that caused the dispersal was the addition of water to the plant. Thus the explosive dispersal would most likely occur during or after rainfall.

It quite the evolutionary solution! Rather than being limited by water and distance these plants have evolved a strategy to undergo sexual reproduction with greater success. If there is not a film of water uniting one plant with a mate, then they toss their sperm into the air after a little bit of rain and they might get lucky. Checkout the video below.

Shimamura, M., Yamaguchi, T. & Deguchi, H. 2008. Airborne sperm of Conocephalum conicum (Conocephalaceae). J. Plant Res. 121: 69-71.