Abstract
Seed biology plays a crucial role in understanding plant reproduction, adaptation, and persistence in natural ecosystems. Studies of rare and endemic species are particularly important because information on their reproductive characteristics remains limited. The present study provides the first assessment of seed mass and hydration properties of the rare endemic species Mediasia macrophylla (Apiaceae). The aim of the study was to analyze seed mass, investigate imbibition dynamics, and visually assess changes in seed appearance during hydration. The research was focused on obtaining quantitative data on seed mass and water uptake characteristics as important components of the species’ reproductive biology. The methodology included macromorphological analysis using light microscopy, gravimetric determination of seed mass using batches of 100 seeds, and a gravimetric water uptake test with mass measurements recorded after 1, 3, 6, and 24 hours of soaking.