Dept.Higher Plants, Biological Faculty, M.V.Lomonosov Moscow University, Vorob'evy Gory, Moscow 119899, Russia

Abstract

Different reduction phenomena in inflorescence are suggested to divide into two groups: reduction in pseudocycle lines (reduction of element number in floral units (FU) and reduction outside pseudocycle lines (deadlock reduction of element number in FU). The interpretation of reduction phenomenon as oligomerisation and abbreviation considered for zoological material is not effective for inflorescence. They can be applied only to some parts of inflorescence that have a high level of integrity, i.e. specialised FU. The interpretation of reduction as phenomenon leads the obligatory decrease in general number of flowers in inflorescence (sinflorescence) seems to be not well founded because of high compensation potential connected with paracladium branching. In some cases the reduction of inflorescence elements is a secondary result of reorganisation of complex correlations that manage the morphogenesis in inflorescence or some of its elements. Sometimes reductions lead to very deep changes of inflorescence structure. Their correct typology and comparison with inflorescence of related forms seems to be almost impossible without analysis of morphological lines and possible ways and form of reduction processes.