The investigations on mechanical properties of reed stems face numerous difficulties, because of their anisotropy, heterogeneity, shell-like structure, small lateral dimensions of stems and huge diversity of species and habitats of origination. Aware of all difficulties to cope with, the basic experiment has been conducted, that is the uni-axial tension test for reed stems, withand without joints. The strain-stress relation, at tension, displayed an exponential character, showing material stiffening with the growth of strain. Test results incline to conclusion, that stem-pieces without joints are equally stiff as pieces with joints, however, they are twice as strong as the latter. It means, that joints can be perceived as fragile (in the sense: “brittle”) discontinuity in structure of reed stems. The results of the test have been put through critical estimate and analysis tending to statistical modelling of the load-carrying ability of reed stems.

153-168