Field of Science

Mosses in a Magazine

An article came out this month in the New Life Journal about gardening with mosses. This article was written by of Mountain Moss in North Carolina.

The article has some good moss biology tucked among the gardening tips. She discusses the fact that mosses do not have roots and instead have rhizoids to attach them to the soil. Also she touches on the fact that mosses do not have xylem cells to move water inside their plant body.

Another interesting tidbit that she shares is that mosses can even be seen in the 5000 year old gardens in Kyoto, Japan. I linked to the article that she cited, because I was interested to see if they were talking about the moss temple (Saiho-ji). I visited this temple while I was in Japan this past summer and I was excited to hear what they had to say about it. (Click here for a link to my post about the Saiho-ji temple in Kyoto.)

I was surprised to discover that the Smithsonian Magazine article that she cited did not mention the Saiho-ji temple. Instead it focused on the Ryoan-ji temple (the temple of the peaceful dragon). The focal point of this temple is a zen rock garden that has a number of rocks and mosses surrounded by raked stones.

This is one of the temples in Kyoto that I visited in addition to the Saiho-ji temple. There were not nearly as many mosses as the moss temple, but being that it was a zen aesthetic, less is more. The zen rock garden was very peaceful looking place and my photos capture its true essence.

However being there was quite a different exprience. All the visitiors to the garden sit on a large wooden porch overlooking the area shown here in the photos. You might think that everyone would be sitting quietly meditating as they stare at the stones. If that is what you imagined then you would be wrong. It is more like 40 foreigners sitting on the porch chatting loudly, some of them talking on their cell phones, while the zen stones stare back in dismay.

I was really surprised that they didn't have some sort of talking rules to encourage a meditative atmosphere. Oh well, I will just have to enjoy the meditative experience from my silent photos. It's a little sad that they are better than the actual experience, but I am glad to have gone and given it a try.

Some More Mosses from Japan

While in Japan I traveled to the small town of Nozawa Onsen. It is about an hour north of Nagano, via train and then bus. Nozawa is nestled in the mountains and is famous for the many onsen (hot springs) that dot the village. I hear that it is also a great place to ski and we saw many ski lifts heading up into the surrounding mountains. While walking around town we visited a shrine that was surrounded by moss.

However, I did not collect any mosses. I am not sure what the karma impact might be from collecting moss from the grounds of a shrine. So I just took some pictures instead.

The photo to the right is a member of the Orthotricaceae. All of the little tan/brown structures are the sporophytes. The Orthotricaceae are recognized by their short sporophytes with upright capsules. Typically they grow on tree bark or rocks and have dark green gametophytes that can sometimes appear black when dry.

Sculptures on the grounds of the shrine were covered in mosses!

These a a couple of shots of some Fissidens sp. Members of this genus have a really gorgeous morphology! The leaves do not spiral around the stem as in most mosses. In Fissidens they have a distichous leaf arrangement, meaning that they are positioned 180 degrees opposite each other on the stem. It is the same leaf arrangement that you see in Iris plants. This distintictive pattern of leaves makes mosses in the genus Fissidens stand out from other species in the field.

Examining Moss Filaments: Protonema & Rhizoids

Every week members of the Goffinet Laboratory group meet to discuss a research journal article about bryophytes. The papers that we read range from morphological to molecular and may relate to either mosses, hornworts, or liverworts, all of which we study in the laboratory. Last week's paper focused on moss protonema and rhizoids.

Protonema are unicellular filaments of haploid/gametophyte tissue. In the moss life cycle a spore germinates to produce filamentous protonema that then develop into leafy gametophytes. At right is a photograph of the protonema of Funaria hygrometrica.

Blogging on Peer-Reviewed ResearchPressel, S., Ligrone, R. and J. G. Duckett. 2008. Cellular Differentiation in Moss Protonemata: A Morphological and Experimental Study. Annals of Botany 102:227-245.

This research paper focuses on three types of bryophyte filaments: chloronema and caulonema (both types of protonema) and rhizoids. They define rhizoids as filaments that are produced only by the mature leafy gametophyte plants. They are often pigmented brown and function to attach the gametophyte to the substrate (soil, tree bark, or rock that they are growing on).

They had a number of goals for their research, but I am not going to go into all of them. The one that I found the most interesting was that they examined 200 moss species and determined the cellular changes that occur during differentiation of the caulonema and rhizoid filaments. (Differentiation is the process by which cells acquire all of the characteristics that they will have at maturity.) You may ask why just describe a maturation process inside of the cells. Well as the authors mention (and I wholeheartedly agree), it is important to describe the sequence of events that occur in these filaments because it lays the foundation for future experiments. Researchers have to know how structures develop normally, so that they have a control/baseline to compare to experiments.

Additionally, the paper is full of great images. There are light microscopy photos zoomed in to the point that you can see the nucleus inside of the cell. Some of the other images illustrate a feature that I had not heard of before. The rhizoids produce a mucilage sheath (i.e. slime) that covers the entire outside of the cell wall. The remainder of the images are transmission electron micrographs that show all sorts of cellular structures. You can see mitochondria, chloroplasts, golgi bodies and nuclei, just to name a few. In order to see these structures some serious magnification is needed. These organelles are probably magnified 10,000-50,000X. I think that it is just really fabulous that we can see all of these tiny biological features inside of the cells!