STUDY OF ASTRAGALUS INFLORESCENCES BY THE METHOD OF LOGICAL OPPORTUNITIES

The giant genus Astragalus can be considered an appropriate model for applying ZAVARZIN's approach known as ''space of logical opportunities ''. In the present paper, the attempt is made to analyze the diversity of flower arrangement types in this genus, constructing such a ''spac e'' on the basis of independent combinations of 5 parameters: 1) conti nuity vs. discontinuity of the floral zone; 2) many lateral racemes vs . 1-2 lateral racemes in a floral zone; 3) rosette vs. semi-rosette vs . elongated main axis; 4) racemes multiflorous vs. pauciflorous; 5) ra cemes with long vs. short peduncles. The overall number of the theoret ically possible combinations of these parameters is 48, but only 37 re ally do occur. The absence of the other 11 variants is probably due to morphogenetic constraints.