When?

Since this past September, I spend 2 hours of the last Saturday of every month attending and teaching a moss study group in Baltimore. It is a rare occurrence to find a group that studies moss for the fun of it - and no less a miracle that its within driving distance!

We are not a very structured organization; just a group of 10 or 15 people from all over Maryland. We spend our time identifying field and microscopic characteristics of these mosses. We use Crum's book, Mosses of the Great Lakes Forest to key out these plants. Don't ask me why we use this book, but I had no complaints since it happened to be my textbook in college. My personal favorite is Mosses of Eastern North America, but I don't own either volume...yet.

This month we had many newbies so that always calls for a brief beginners review and that is where I will begin here. Strap on your seat belts and get ready for part 1 of my 6 part series: Better Know Your Mosses! (credit to Stephen Colbert for that title)

When did mosses appear?

They emerged around 350 million years ago during the Devonian period. To put it in perspective, vascular plants didn't come around until about 140 million years ago during the Cretaceous period, so mosses were happily photosynthesizing for over 200 million years before trees, shrubs and herbaceous plants ever existed - it blows the mind!



Muscinae from Ernst Haeckel's Kunstformen der Natur, 1904

This painting demonstrates not only the diversity of mosses when they first started colonizing land, but also the fact that over these last millions of years they really haven't changed at all: they got it right the first time around. Now at first glance, this painting seems a bit exaggerated, and it is, but really only in the scale of the plants and the fact that those species would not live anywhere near each other based on their prefered environmental conditions. Aside from that, the Polytrichum, Sphagnum, Andreaeobryum, Ptillidium, Mnium, et cetera that you see here look pretty much the same today.

There are approximately 22,000 species of mosses worldwide that comprise 3 classes: Bryopsida, Sphagnopsida and Andreaeopsida (for all you taxonomists out there, there may or may not be more classes depending on if you are a lumper or splitter!). Bryopsida includes the true mosses (my real focus). The other 2 classes have only one genus each: Sphagnum and Andreaeobryum. Moving up the phylogenetic tree, these 3 classes are found under the Division Bryophyta. The other bryophytes can be found in Divisions Hepatophyta and Anthocerotophyta (liverworts and hornworts respectively). And all these ranks fit nicely under Kingdom Plantae. Ta-dah!

Sometimes it feels good to regurgitate this stuff...