关键词: 无患子科, 七叶树科, 槭树科, 叶表皮, 系统学意义

Abstract:

Leaf epidermis of 33 species representing 25 genera of Sapindaceae, 2 species of Hippocastanaceae and 4 species of 2 genera of Aceraceae was investigated using light microscopy (LM) and scanning electron microscopy (SEM). The shapes of leaf epidermal cells of these three families are usually polygonal or irregular ; the patterns of anticlinal walls are straight , arched or sinuolate . The stomatal apparatuses, only present on the abaxial epidermis for all sampled species ( except for Cardiospermum halicacabum and Eurycorymbus cavaleriei), can be assigned into six types. The anomocytic type, occurring in 16 species ( Allophylus caudate, Handeliodendron bodinieri, and Delavaya toxocarpa , etc .) is very common; the actinocytic type, occurring in 11 species ( Amesiodendron chinense, Aesculus chinensis, Dipteronia sinensis, etc .), and the cyclocytic type , occurring in 6 species ( Dimocarpus longan, Litchi chinensis, Nephelium chryseum) are comparatively common; whereas the other three types can be considered diagnostic of several genera, such as hemiparacytic type for Aphania oligophylla, Pometia tomentosa and Xerospermum bonii , Harpullia cupaniodes, staurocytic type mainly for Pavieasia kwangsiensis, and anisocytic type only for Cardiospermum halicacabum. Under SEM the cuticular layer of the leaf epidermis is striated, scaly or granular; the inner margin of outer stomatal rim of most species of these three families is undulate . The close relationships among Sapindaceae , Hippocastanaceae and Aceraceae are supported by the evidence from leaf epidermis .

Key words: Sapindaceae