Abstract
The developmental cycle of Mercurialis perennis L. polycormones lasts about 6 years. Under natural conditions polycormones arise by way of vegetative propagation. Their development and growth depend on the age, size and developmental state of the part of the plant from which the new individual arises. Development of the polycormone is most intensive in the first three years. During that time the young individuals increase their number of above-ground and underground shoots according to geometrical progression. A certain stabilization in growth and spread was observed in the 4th and 5th year of life. At that time the polycormones are of spherical or oval shape and their structure is mono- and polycentric. Their surface area is 0.51-2.0 m2 and the number of above-ground shoots amounts to 80-200. In the following years the intensity of regeneration decreases. Polycormones developing in garden culture reach their senile phase in the 3rd and 4th year of life, whereas in natural conditions in the 5th and 6th year. Then gradual dying of the oldest parts of the polycormone starts its division into several independent units. The rapid increase of the area occupied by the newly arising individuals leads to obliteration of the boundaries between them. The development of the aggregation-field distribution specific for this species is preceded by random and aggregation-random distribution of the polycormones in the Tilio-Carpinetum herb layer. It is evaluated that compact one-species patches of Mercurialis parennis L. form in forest communities in about 10 years.