Keywords:  Bidens frondosa L., ontogenetic structure, population

// Мелиорация. – 2018. – №1(83).– P. 71—76

During vegetation period plants of Bidens frondosa L. change its ontogenetic state and morphometric parameters such as height, number of pairs of leaves, length of leaf change too. The highest aerial phytomass, the thickness of the shoot, the number inflorescences and the number of seeds in one inflorescence, the mass of 100 seeds in the first population were higher than in the rest ones. In ontogenetic structure there are a few species of the follow age status: sprouts, juvenile, immature, virgin and generative plants. Their quantitative relationships change as the seasonal rhythm of development passes.