关键词: 芡, 个体发育, 器官发育顺序, 下胚轴毛

Abstract: The early stage(from heart shape embryo to seedling) of ontogeny of Eurgale ferox Salisb.is presented in this paper. The embryo from heart stage to mature stage is expressed as the shoot apex develops firstly and the root apex develops very weakly, at the nodes of lst and 2nd plumular leaves some nodal root primordia develop before radicle and there is no obvious differentiation in radicle.The characters expressed from seed embryo to seedling are as follows. When the seed germinates, 4 polyseriate branched hairs arise from the end of the very short hypocotyl. At seedling stage, nodal roots develop before radicle and the growth of the radicle ceases only about 1mm long. These characters of developmental sequence on organogeny are very peculiar to anqiosperms and should be primitive in phylogeny. The hypocotyl hair may be is a general character in aquatic or hygrophytic angiosperms and a indicative character to differentiate radicle and hypocotyl.

Key words: Euryale ferox, Ontogeny, Organogenetic development sequence, Hypocotyl hair