Stratiotes aloides L. seeds need neither light, nor oxygen, nor vernal
ization to germinate but the germlings need light and oxygen for furth
er development. Germination, however, is delayed strongly by the mecha
nical resistance of the seed coat. After liberation from the fruit see
ds float probably because small gas bubbles are trapped between the ha
irs of the seed coats. The different stages of seedling development ar
e described.