Last Saturday, Dr. Joan Hudson, Associated Professor of Biology at Sam Houston State University and editor of the Fiddlehead Forum, provide a presentation on the sexual reproductive cycles of Selaginellas and Lycopodiums to the Texas Gulf Coast Fern Society. We have avid growers of these genus' in our group. I especially enjoyed being able to see the megaspores and micro spores under microscopes. I found your information quite interesting. I believe I noted that sub-genus growing in the Big Thicket area of East Texas. Not being familiar with Tetragonostachys, I thought they were likely a form of sphagnum.

`The genus Selaginella is comprised of three basic subgroups, identified as subgenuses. These are Selaginella, Stachygynandrum, and Tetragonostachys. The subgenus Selaginella consists of one native species, S. selaginoides, the subgenus Stachygynandrum of seven native species, and the subgenus Tetragonostachys of 26 natives and 1 hybrid native. Texas has three species of the Stachygynandrum and nine species, maybe ten, of the Tetragonostachys. Most of the species occur in the western portion of Texas with one, S. apoda, found in eastern Texas.
Most Selaginellas, and Lycopodiums too, that are grown are from tropical areas and are not native North American species. Not all that much is known about the habitats of our native species. Growing either, especially the native Lycopodiums, can be quite challenging if you approach them from the point of view that they can be treated like any angiospermous plant, which, of course, they are not. Thus my interest in sharing my experiences in their cultivation.