Abstract: There are two flowering modes in Actaea asiatica (Ranunculaceae). In the first mode, the sepals are caducous and the anthers are physically isolated from the stigmas as in most out-breeding, bisexual species in this genus. The second flowering mode leads to mechanical self-pollination (autogamy). The sepals do not open or fall off from the flower, but are only dletached from the floral receptacle. The staminal filaments elongate to push the anthers in between the stigma and the withered sepals. The latter press the dehiscent anthers onto the large stigma, which results in mechanical autogamy. The results of our bagging tests showed that the highest seed set resulted from spontaneous self-pollination in A. asiatica, but no seed set was found as a result of apomixis or anemophily (via air currents). This species is obviously self-compatible and obligate autogamy.