During one scene in the university laboratory when Peter is (partly) explaining to Frank why the fossilized man is so important, he mentions that sphagnum is a polysaccharide. For those of you who are not fluent in chemistry, a polysaccharide is a general term for a large molecule composed of several linked sugar molecules (such as glucose, for example). However, sphagnum is no such thing, it is a type of moss, nothing more. Its chemical composition does slow down the decomposition of living tissue but the chemical substances involved are mostly tannins, which are unrelated to polysaccharides.
It's established early on that Frank doesn't speak German, yet he appears to understand when Det. Heim's partner says "We should take them in."