In the case of the mosses Rhytidiadelphus squarrosus, R. triquetrus and Mni
um hornum it could be demonstrated that the concentration of biflavonoids a
nd coumestanes show seasonal variation. This is correlated with the periods
of active growth. Independently the concentrations are also subject to the
light intensity at the habitat, (C) 1999 Elsevier Science Ltd. All rights
reserved.