Relevance. The degree of variability of the linear parameters of the morphological elements of the seeds of the anise (variety Vityaz) and cumin (variety Peresvet).Materials and methods. 1) Plants: Monarda fistulosa L. (the breeding sample №5 U.P.), Monarda citriodora Cerv. ex Lag. (Simka variety), Melissa officinalis L. (Zhemchuzhina variety). 2) secondary metabolites: flavonoid glycoside linarozid and steroid glycoside moldstim.Methods. The studies were carried out in VNIIO – a branch of the FSBSI Federal Scientific Vegetable Center. The measurement of the length of the seed and endosperm was carried out using a caliper (GOST 166-89). The embryo length was determined using a Levenhuk 670T microscope and a DCM 300 MD video eyepiece at Ч 40 magnification using Scope Photo (Image Software V. 3.1.386). The lengths of each seed, endosperm (longitudinal section) and embryo (after isolation) were sequentially analyzed. The indices IE/C, IZ/E, IZ/C were calculated as the corresponding ratios of the length of the seed, endosperm and embryo.Results. The maximum length of the seed (4.76±0.10 mm) and of the endosperm (4.08 ± 0.08 mm) and the length of the embryo (1.40±0.02 mm) were noted in cumin seeds. The average values of the coefficient of variation (V), on the contrary, were minimal for cumin seeds, varying from 7.8% for the length of the embryo to 11.5% for the length of the seed. The average values of the coefficient of variation (V) for anise varied from 9.3% for the length of the embryo to 14.7% for the length of the seed. The maximum level of variability in both cultures was noted for seed size. Correlation analysis showed that a close relationship was observed in anise (r=0.912) and cumin seeds (r=0.876) only between the length of the seed and the length of the endosperm. The value of the correlation coefficient (r) between the linear sizes of the seed and the embryo was 0.195 for anise and 0.229 for cumin seeds, and between the length of the endosperm and the length of the embryo, 0.237 and 0.214, respectively. The correlation coefficient (r) between the index IZ/E and the linear sizes of the seed, endosperm and embryo had low negative values from -0.221 to - 0.345.