Abstract: The pollen of 23 species of Trillium was examined by LM, SEM and TEM. The result showed that the pollen shape, the size and the aperture type are similar basically, characterized by spherical or subspherical pollen grains, inaperturate, size ranging from 20-38 urn in diameter. The exine sculpture, however, shows different and four types are recognized, i.e., granulate-, verrucate-, starred-and spinulate types. The wall exine stratification is faint in most species except T. grandiflorum and T. catesbaei which have obvious tectum and collumellae in wall structure. T. lancifolia and T. lanceolatum have different sculpture, the former has granulate sculpture.the latter starred sculpture .Palynology suggests that the two species be treated as separate species.

Key words: Pollen morphology

摘要： 对延龄草属(Trillium L.)23种进行了光镜和电镜的观察研究。其中14种作了透射电镜的研究。研究结果表明，本属花粉的形状和大小在种间变化不大，但在外壁纹饰上却有较大的差异，大致可分为4个纹饰类型，即颗粒状纹饰（多数种类），疣状纹饰，星状纹饰及刺状纹饰。外壁结构上，大多数种类结构层次模糊，无明显的复盖层和柱状层分化。但 T.grandiflorum和T.catesbaei 2个种则有较明显的复盖层和柱状层的分化。T.lancifolia和T.lanceolatum具有截然不同的纹饰特征，前者为颗粒状纹饰，后者为星状纹饰。从孢粉学考虑这2个种不宜合并，应独立为2个种。本文还对产于亚洲和北美的种类进行了比较和讨论。

关键词: 延龄草属, 花粉形态