Timmia megapolitana

Here are some photos of the moss Timmia megapolitana, the species that I worked on for my Master's Thesis.  Its common name is the Indian Feather Moss, due to the calyptra that remains atop the sporophyte capsule, sticking up like a feather. (It really isn't a very politically correct common name. Maybe we could come up with something better. How about the Periscope Moss? Any other ideas?)

Anyway these are some photos that I took of the plants and my fieldsite out in Albany, New York. This was several years back and before I owned a digital camera. Thus the images are a little rough, since they are scans of prints. This species grows on calcium rich substrates. This area has a lot of limestone. The mosses grew on the sides of fissures in the rock (below right) or on the sides of small ledges (below left). I also found this species growing at an abandoned marble quarry in Vermont, another substrate that has a basic pH and is calcium rich. 

Timmia Peristome

This is an image that I submitted to the http://www.botany.org/plantimages/ImageData.asp?IDN=ca07-029Botanical Society of America's student image competition last summer. I was very surprised and excited to be awarded second place in the competition. All of the images submitted in the competition were added to the society's online image collection, which is available for nonprofit educational or private non-commercial uses.

Below is the description of this image that I used for the competition.
Have a Happy Thanksgiving!

The peristome is located around (peri-) the mouth (-stome) of the moss capsule, a structure which contains the spores. For the past 200 years, peristome characteristics have played an important role in defining major groups of mosses. The peristome shown here has a unique morphology and is an identifying feature for the Timmiaceae. This scanning electron micrograph of Timmia megapolitana has been colored to highlight the two layers of the peristome. The endostome (inner layer, colored in orange) consists of a membrane that is topped by 64 filaments, while the exostome (outer layer, colored in yellow) consists of 16 large teeth. These teeth have the ability to move in response to humidity, thus opening and closing the mouth of the moss capsule. This movement facilitates the release of spores (colored in green) under optimal dispersal conditions.