The Mystery of the Missing Moss

This is a tale of a small group of mosses in the genus Sorapilla. Over the past 150 years they were located by scientists only a handful of times in the wild. That is until recently. A undergraduate student found a population of Sorapilla papuana in Queensland, Australia. 

The real mystery about these mosses is determining its closest relatives. It has a very unique morphology = (exterior size and shape), which has helped researchers come up with hypotheses about its relatives. This new discovery of live mosses means that DNA can be extracted from the plants and used to test these ideas, potentially resolving the conundrum of Sorapilla's relatives.

Honestly I had never known about this genus before hearing about it's recent re-discovery. The article (linked to above) alludes to its unique morphology and I was interested to learn more about it. These mosses grow in tropical regions, so off I went to my Guide to the Bryophytes of Tropical America. To my surprise and delight I discovered that Sorapilla mimics some of my favorite mosses, the Fissidentaceae. 

Both Sorapilla and the Fissidentaceae have leaves in two-ranks, meaning they have a row that runs along the right side of the stem opposite a row that runs down the left side. Most mosses have leaves that spiral around the stem, sticking off in all possible directions. The other cool feature about the leaves is that they are divided into two regions a single layered lamina at the top and a region below where the leaf forks, creating a pocket that clasps the leaf above it. Based on my reading, these are the only two groups of mosses with this type of leaf. Despite these similarities, other features of the sporophyte indicate that Sorapilla and the Fissidentaceae are not closely related. I am really excited to hear what the findings are from the DNA data and which mosses are the closest relatives of Sorapilla. If in the end it is not a close relative of the Fissidentaceae, then it will be another cool example of convergent evolution. Two distantly related species evolving similar morphologies.  

Click here for a link to an image of Sorapilla papuana. 
Not to be confused with sopapillas, the tasty fried pastry.

For comparison, this is a photo of Fissidens that
I took while hiking in the Sierra Nevada Mountains. 

I find it a funny irony that the closest town to the population of the rediscovered moss is called Mossman. It sounds like a town full or moss super heros. MossMan! However, the town name was originally Mosman, so it probably wasn't named for moss plants.  

Hat tip to Dr. Tobias Landberg for sending me the article about this discovery.