Background/Question/Methods  
Ranunculus kadzusensis is an aquatic plant but can live both under the water and on the ground as different ecotypes. R. kadzusensis is categorized as an endangered species by the Wildlife Protection Act in South Korea (Ministry of Environment of Korea 2005). Though there were no records of observation of R. kadzusensis from 1970 to 1990, recently, many habitats were discovered in the rice paddy lands and ditches near the western coastal area of Korean peninsula. However, there are few studies of taxonomy and ecological traits of R. kadzusensis. Therefore this study investigated the effect of several factors on seed germination and morphology of R. kadzusensis.
Community survey conducted in main habitats of R. kadzusensis (Ganghwa, Incheon) in 2007 and 2008. The germination of R. kadzusensis seeds was tested for seed size (500~600 μm, 600~700 μm and 700 μm~800 μm) and after light (10 h dark : 14 h light photoperiod and complete darkness), salinity (0.5%, 1.0%, 1.5%, 2.0% and 2.5% solutions of NaCl) and temperature (15:20°C and 20:30°C) treatment. Changes of morphology to water depth (0 cm, 20 cm, 50 cm and 100 cm) and light intensity (100%, 40% and 10%) have been investigated.
Results/Conclusions  
There were positive correlation between the pedicel number and each of biomass and coverage of R. kadzusensis. Germination rate was relatively high regardless of seed size and light treatment but decreased to salinity stress and high temperature (20:30°C) treatment. Morphologically, R. kadzusensis in the water had taller height, longer leaf and less root number than that on the ground. Biomass and pedicel number were decreased and height was increased by increasing of shading rates. It is suggested that more studies to figure out the causes of decrease of R. kadzusensis and conserve this species in South Korea are needed.