Field of Science

Berry Go Round #26

The latest edition of the plant carnival Berry Go Round has been posted at Gravity's Rainbow. The theme for this edition is springtime. We have been experiencing a lot of those spring showers here in Connecticut lately. I am most definitely ready for some sunny spring weather for a change. But in the meantime check out the spring-spirit at the carnival. One of my posts from this past month was featured in the lineup. It is the post about the number of moss species worldwide.  

For more about blog carnivals and my posts about the earlier editions of Berry Go Round, click here.

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.

Connecticut Botanical Society Workshop

Saturday April 17, 2010 - 9:30am-12:30pm
Nature Center, 269 Oak Grove Street, Manchester, CT

I will be leading this workshop sponsored by the Connecticut Botanical Society next month. It is free and open to the public. Space is limited to 14 people, so if you are interested in attending please contact me.

Have you every walked through the woods to observe a carpet of mosses? Upon closer inspection you notice that there are a wide variety of patterns, shapes, and colors within such a small amount of space. In this session you will learn how to indentify and explore mosses. This introduction to mosses will be based upon properties that can be observed with a hand lens. Participants should wear sturdy shoes and dress for the weather. After the indoor introduction we will car pool to the field site (Bolton Notch State Park).  Coffee and light refreshments will be available at the start of the workshop.

Call or email Jessica Budke to register -  (860) 486-6306 

(Update 10 April 2010 - The Workshop is currently full. If you would like to be placed on the wait list feel free to contact me.)

My Bryology Bookshelf - II

Another book on my shelf is Gardening with Moss by F. F. Rockwell. I am not sure when I picked up this book, but there it was hiding on the shelf and I decided to give it another look...

And now I remember why I cannot recall when I picked up this book. The title is quite deceiving! You might think that it is another book about growing mosses in your garden similar to these two (here and here) that I have discussed before. But no, this book was written in the 1920's and the title should be 'How to use Peat Moss (Sphagnum) when Gardening Flowering Plants'. It is interesting as a historic text. The first chapter is all about peat moss and its utility in the garden. This chapter also features a nice story about the author's first meeting with peat moss. From what I can tell the rest of the book does have sound gardening advice, but it is probably the same information that you could get from a more recent book.

Overall I wouldn't recommend it if you are looking for a book on Moss Gardening, but as a history or gardening buff it might prove interesting. You can check out a limited preview of the book here at GoogleBooks.  


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.


My Bryology Bookshelf - I

I recently started a list of recommended bryology books on my sidebar. However I wasn't sure how many of these books I had talked about in actual blog posts. So I decided to start up a group of posts that walk through the bryology books on my shelf.

I also wrote about the fabulous bryophyte dictionary, Mosses and Other Bryophytes, an Illustrated Glossary by Bill and Nancy Malcolm.

One of the books on my list that I have yet to talk about is my advisor's most recent book Introduction to Bryophytes by Alain Vanderpoorten and Bernard Goffinet.

When I helped teach and Undergraduate Course in Bryology a few years back we could have really used this text. We used some excerpts from the book Bryophyte Biology. I think that this is a great book too. Unfortunately it is pretty tough for the average undergraduate. Bryophyte Biology is geared more for a graduate student or professional audience.

I have yet to use the new book Introduction to Bryophytes to teach, but I think that it will work really well for that purpose. It is aimed at undergraduate biology students or science savvy amateurs. I have also used the book to hunt up some fun bryology facts for use during my moss walks. If you want to really dig into all the different types of bryophytes and their morphology then this is probably not the text for that endeavor. However it is a look at the biology of bryophytes from a number of different angles, such as Physiology, Conservation, Ecology, Biogeography and Evolution. 

Berry Go Round #25

The latest edition of the plant carnival Berry Go Round has been posted at Foothills Fancies. Since it is the February edition there is a fun chocolate-y theme throughout. Beware of reading if you have a sweet tooth or if it is before lunch. I almost decided to have a chocolate dessert before my lunch when I read the carnival this morning. 

One of my posts from this past month has been included in the lineup! It is the post where I discuss a new moss gardening book. BGR also mentioned that I recommended checking out the moss-cam. I have heard about the moss camera project that is run by researchers out in California, but I have not discussed it on my blog, nor do I have a link to it anywhere that I can see. I think that the credit for mentioning/blogging about the moss-cam should go to Dr. Lalita Calabria who has recently started a blog called "Adventures of a Phytochemist".  She has an extensive post about mosses and I think that might explain the confusion.

For more about blog carnivals and my posts about the earlier editions of Berry Go Round, click here.

How many mosses are there?

One of my bryology students told me that their friend could not believe that they were taking a course on mosses. Their friend's comment was that there is only one type of moss, right? The small green kind.

This question boggles my mind. Is there only one kind of bird? No. One kind of tree? No. One kind of moss? No. You have to get pretty specific in your definition of any living plant or animal before the answer to that type of question is yes. For example, is there only one kind of ostrich? Yes. Only one sugar maple tree? Yes. You get the idea.

So my point is there are many different types/species of mosses in the world. Just take a look at some patches of moss when you are out and about. I bet that when you get close to the mosses and really peer at them you will notice that the first patch does not look exactly the same as the the second patch.

The question that I more often get but have a hard time answering is, "How many species of mosses are there worldwide?". This presents a problem, because it depends on who you ask and whether they are a splitter or a lumper. (Basically - A splitter is a scientist who tends to find differences between organisms and then groups them in a way that creates more species. A lumper is a scientist who would look at the same organisms focus on the the similarities and then group them in a way that creates fewer or one species.) Those are not technical biology terms and these are my own informal definitions, but if you were to use either of them with a biologist who thinks about species they will most likely know what you mean.

In the end this makes for a difficult question  "How many species of mosses are there worldwide?" I have looked through a number of bryology and botany books on my shelves and here is the range of answers to this question. (The quotations are arranged in chronological order.)

Bryophyta by Parihar (1961) p.150 "... about 660 genera and 14,500 species."
The Structure and Life of Bryophytes by Watson (1971) p.16 "Some 14,000 species of moss are known and the great majority are sufficiently alike in structure to create a real difficulty for the taxonomist."
Biology of Plants by Raven, Evert and Eichhorn (1999) p.412  " least 9500 species of mosses, with new forms being discovered constantly, especially in the tropics."  

A Checklist of the Mosses by Crosby, Magill, Allen, and He (1999) p.1 "This Checklist recognizes 12,754 species. Although new species of mosses continue to be described, the number being recognized appears to be declining, because of increased synonomy."

Introduction to Bryology by Schofield (2001) p.10 "... contains approximately 10,000 species in nearly 700 genera."

Bryophyte Biology edited by Goffinet and Shaw (2009) Ch. 2 p.56 "With approximately 13,000 species, the Bryophyta compose the second most diverse phylum of land plants."

Introduction to Bryophytes by Vanderpoorten and Goffinet (2009) p.70 "Approximately 12,000 species are currently recognized,..."

From this survey we end up with an answer that ranges from 9500-14500 species of mosses. Scientists are usually comfortable with a high level of uncertainty so they may find that range a sufficient answer. Remember it's not as though there is a right answer and by giving a range scientists just don't know. The number of species is constantly changing as new ones are discovered and others may go extinct. It also depends on which expert you consult (splitter or lumper). So the answer to this question is in a constant state of fluctuation. 

I find that giving a single number is more satisfying if I do not want to go in the the whole explanation that I have given here. Usually I say that there are approximately 12,500 species of mosses and I quote A Checklist of the Mosses as my source. This count is going on ten years old at this point, but I think that it is the most accurate count that we currently have. It also looks like the two books from 2009 are following this count as well with their values that are a little above and below those of the checklist.

So, "How many species of mosses are there worldwide?" you may ask.

To that I would answer that there are approximately 12,500 (Crosby et al 1999).