About Selaginella sibirica (Milde) Hieron.
Selaginella sibirica, commonly called the Siberian spikemoss, is a species of spikemoss. It grows on dry or exposed rocks and ridges, with a range extending from Alaska to the northwestern part of the District of Mackenzie, and also occurs in northern Russia. Its leaves are linear, grooved on the back, 2.5 to 3 millimeters long when including the seta, and are usually truncate near the tip. Its sporophylls are ovate to triangular, and shorter than the plant's leaves. This species closely resembles Selaginella densa, but can be distinguished by its white setae; S. densa has yellow setae instead. While all known North American specimens of Selaginella sibirica share the same typical traits, R.M. Tryon identified a variant form in Asia that has longer, orange-brown setae rather than the typical white setae.
