Abstract: Epidermal characters of mature leaves in 9 species belonging to 6 genera of Ulmaecae were investigated with the help of epidermal maceration and light microscope.The results show that the stomatal apparatus are anomocytic and exist only on the abaxial epidermis in 9 species.Trichomes are mainly divided into glandular hair and non glandular hair.Glandular hairs consist of 1 basal cell, 2~4 stalk cells and 2~4 dilated head cells.Non glandular hairs are developed from one cell, yellow cystolith is often found at the base of the trichome, some hairs are very short and take on beaked shape, another hairs are long wimble shape.Based on the above morphological characters, it is not reasonable that Ulmaceae (sensu lato) was divided into two independent families.Meanwhile, the shape of epidermal cells, the pattern of trichomes and the characters of stomatal apparatus vary obviously with species and genera.

Key words: Ulmaceae, leaf epidermis, stomatal apparatus, trichome

摘要： 利用叶表皮离析法观察了榆科6属9种植物叶片的表皮结构。结果表明,榆科植物叶片气孔器仅分布在远轴面,不规则型,不具副卫细胞;叶片毛状体主要有腺毛和非腺毛两种类型,腺毛由基细胞、柄细胞和膨大的顶细胞构成,非腺毛均由单细胞发育而来,基部具或不具钟乳体,多数非腺毛顶部发育成长锥状,少数非腺毛顶部极短呈喙状。根据气孔器的类型和分布位置,尤其是表皮毛的基本结构和发育类型等特征,不支持将广义榆科分为两个独立科的观点。但榆科这9种植物叶表皮特征具有属间或种间差异,有一定的分类学价值。

关键词: 榆科, 叶表皮, 气孔器, 毛状体