 The spores remain dormant inside the sporocarp through unfavorable conditions , but when conditions are suitable and wet , the sporocarp will germinate . It splits into halves , allowing the tissue coiled inside to become hydrated . As this internal tissue swells with water , it pushes the halves of the hard outer covering apart , and emerges as a long gelatinous worm @-@ like sorophore . The sorophore is a sorus @-@ bearing structure unique to the Marsileaceae ; it may extend to more than ten times the length of the sporocarp inside which it was coiled . This extension carries the numerous spore @-@ producing sori attached along each side of the sorophore out into the water . 
