A. Stipe and columella brown or black.
a. The columella scarcely reaching the center of the sporangium.
- 1. Clastoderma. Threads of the capillitium forking several times, but not combined into a network.
- 2. Lamproderma. Threads of the capillitium branching and anastomosing to form a network.
b. The columella extending beyond the center of the sporangium.
- 3. Comatricha. Threads of the capillitium forming only an interior network, attaining the wall by numerous more or less elongated free extremities.
- 4. Stemonitis. Threads of the capillitium forming an interior network of large meshes and a superficial network of smaller meshes.
- 5. Enerthenema. Threads of the capillitium pendent from a discoid membrane at the apex of the columella.
B. Stipe and columella white or yellowish.
- 6. Diachaea. Threads of the capillitium branching and anastomosing to form a network.
I. CLASTODERMA, Blytt. Sporangium regular, globose, stipitate; the wall very thin and fragile. Stipe elongated, tapering upward, entering the sporangium as a very short or nearly obsolete columella. Capillitium arising by a few branches from the apex of the columella, these branches forking several times at a sharp angle, but not combined into a network, the ultimate branchlets long and free, or only connected together at their tips by persistent fragments of the sporangial wall. Spores globose, violaceous.
The claim of this genus to be distinguished from Lamproderma must rest upon the fact that the branchlets of the capillitium do not anastomose and form a network. It is the same as the genus Orthotricha of Wingate.
1. Clastoderma De Baryanum, Blytt. Sporangium very small, globose; the wall early disappearing, except the minute fragments which persist at the extremities of the capillitium, and a narrow collar at the base of the columella. Stipe very long, thick and brown below, tapering upward to a pellucid oblong swelling, thence abruptly narrowed to the apex; the columella extremely short, capillitium of very slender pale-brown semi-pellucid threads, divergently forking, the ultimate branchlets often joined 2–4 together at their tips by fragments of the sporangial wall. Spores globose, even, violaceous, 8–9 mic. in diameter. [See Plate XI, Fig. 25.]