华北地区莴苣属（广义）植物花粉特征的研究

本文研究了华北地区莴苣属（广义）７种植物的花粉形态与微形态特征。结果表明：莴苣属（广义）内这些种具有相同的花粉类型。该属的花粉为球形，３孔沟；极面观为三裂圆形，近六边形；赤道面观为圆形；花粉表面具网状纹饰，同胞１５个，网脊上有许多小穴和规则排列的刺。与邻近属形成明显差异，使该属成为一个自然类群。新属毛鳞菊属ＣｈａｅｔｏｓｅｒｉｓＳｈｉｈｇｅｎ．ｎｏｖ．以其花粉网状纹饰的网脊上具不规则排列的短柱而有别于莴苣属（广义）。花粉的形态特征与微形态特征可为菊科属级水平分类提供重要依据。

PALYNOLOGICAL STUDY OF THE GENUS LACTUCA L.(S.L.)FROM NORTH CHINA

The palynological study of seven species of Lactuca L.(s.l.)from Huabei administrative area of China is presented in the paper.The results indicate: the species within Lactuca L.(s.l.)have the same pollen type.The pollen of the genus is spheroidal with 3 colpori,trilobate round,that is nearly hexagon at polar view and round at equatorial view.There are reticulate veins on the pollen's surface,which have 15 brochi.A lot of perforations and spines arranging regularly distributes on the murus of the reticulate veins.There is obvious difference between Lactuca L.(s.l.)and its adjacent genus,Lactuca L.(s.l.)is a natural taxon.The pollen of Chaetoseris Shih,gen.nov.has small pillars arranging irregular on the murus of the reticulate veins.The new genus is evidently different from Lactuca L.(s.l.).The morphological and micromorphological features of the pollen can provide important basis for the classification at genus level of Compositae.