Androdioecy in Ranunculus ficaria ssp. ficaria (Ranunculaceae)

Androdioecy was for the first time studied in detail in the fibrous-rooted herbaceous ephemeroid polycarpic plant Ranunculus ficaria ssp. ficaria in the Moscow Region during 2019–2023. It has been established that this subspecies produces two types of flowers: perfect and staminate (remains of carpels with reduced non-functioning stigmas are preserved). Perfect flowers and their component parts are always larger than those of staminate flowers. Populations consist of three types of individuals: with perfect flowers exclusively, with perfect and staminate flowers, and with staminate flowers only. Synflorescence of R. ficaria ssp. ficaria is a closed thyrsus, the subunits of which are dichasia. In andromonoecious plants, perfect flowers are located on the top of the thyrsus axis and take a terminal position in paracladial dichasia, while staminate flowers are formed exclusively on the lateral axes of dichasia. In the five studied populations, plants with perfect flowers predominate (from 86.3 to 93.7%). Over a five-year observation period, individuals of different sexual forms did not change the sex of flowers, and the sex ratio in populations remained stable without sharp fluctuations.