SEXUAL POLYMORPHISM OF <i>RANUNCULUS ACRIS</i> (RANUNCULACEAE) IN THE MOSCOW REGION

Abstract

The gynodioecy of the polycarpic Ranunculus acris L. was studied in the Moscow Region. This plant has three types of flowers that differ in androecium structure: perfect flowers (with fertile stamens and carpels), partially male-sterile ones (some of the stamens become staminodes to form sterile pollen), and pistillate ones (an extreme reduction of stamens and the complete absence of fertile pollen). These three types of flowers form a size gradient from the largest perfect to the smallest pistillate ones. Each flower type is formed on separate plants. The share of plants with perfect flowers in 10 studied coenopopulations varied from 43.9 to 53.0%, that of the plants with partially male-sterile flowers from 45.5 to 54.4%. Plants with pistillate flowers are extremely rare (1.5–2.0%). Over three years of observations (2020–2022), we found that the sexual forms of the plants did not change the sex of their flowers, and the sex ratio in the coenopopulations remained stable, without significant fluctuations.