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Since the book is quite old some of the names of the genera are out of date.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.   
 

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.

Two Little Gemmae

So here they are! The long awaited and elusive Tetraphis moss gemmae. These crafty creatures can be difficult to photograph when they are tucked down inside their comfortable gemmae cups. All it takes is a little coaxing from a pair of forceps (aka. tweezers) and they will reluctantly float out into a drop of water. This pair floated together for a perfectly posed picture.

These gemmae are very small, like many moss parts. I didn't measure them, but they are definitely smaller than a millimeter. (maybe a scale bar would be good for next time) Due to their miniature stature, this photo was taken using a compound microscope. From this angle it can be seen that the gemmae are one cell thick near the edges and several cells thick in the center, hence why the light does not shine through in that area. Microscopes are so very great! Those are individual cells that you can see in the photo, with little green chloroplasts inside of them. Chloroplasts are the organelles in the cell where photosynthesis occurs and are the structures that cause plants to appear green. The gemmae are attached to the inside of the gemmae cup via a single strand of cells. A piece of a cell wall from that strand can be seen sticking off to the right, of the gemmae on the right.

The Cup Up Close

This is a zoomed in photo of a couple of Tetraphis gemmae cups. The cups are composed of multiple leaves at the apex of the moss that are overlapping. It is not a solid structure like a teacup. (Just an fyi for your imagination image.) I was hoping that the gemmae would be visible, but they are not unfortunately. They are located in the dark area in the base of the cup.

Gemmae Cups

These cups are located at the apex of the leafy moss and function in reproduction. The moss makes little discs of plant tissue inside the cups called gemmae. These gemmae are moved away from the parental plant via a splash-cup dispersal mechanism. It sounds high tech, but really is just using the power of rain. When rain droplets land in the cup the gemmae are dislodged and can be carried in the water as it splatters away from the moss plant. The gemmae may not be dispersed very far, but it is far enough that this structure is advantageous for the plant to have. This is a from of asexual or clonal reproduction. The plant has made a mini copy of itself that can grow into a new moss plant.

The cups are a common and easily recognized feature of the moss genus Tetraphis. There are two species that can be found in North America, Tetraphis geniculata and Tetraphis pellucida. Tetraphis geniculata is rare and grows in limited northern areas on both coasts of North America. It comes as far south as New Hampshire, but has not been sited in Connecticut. The image I have shown is of Tetraphis pellucida (once again taken at the Goodwin State Forest). This species is widespread across temperate areas of North America and is quite common in Connecticut. It grows most commonly on rotten tree parts (logs or branches) on the forest floor. Its common name is the Four-Toothed Moss.