scyphistoma

noun, plural scy·phis·to·mae, [sahy-fis-tuh-mee] /saɪˈfɪs təˌmi/ scy·phis·to·mas.

1. a stage in the life cycle of a jellyfish or other scyphozoan when it is fixed in place and reproduces asexually to produce free-swimming medusas.

noun plural -mae (-ˌmiː) or -mas

1. a sessile hydra-like individual representing the polyp stage of scyphozoans. It produces forms which become free-swimming jellyfish