蜡梅科植物的叶表皮特征及其在分类上的意义

EPIDERMAL FEATURES OF THE LEAVES OF CALYCANTHACEAE

用扫描电镜和光学显微镜观察了蜡梅科3属5种植物成熟叶片远轴面的表皮特征，认为这些表皮细胞特征和气孔器特征在分类上有比较重要的意义。蜡梅属、夏蜡梅属和美国蜡梅属植物的叶表皮毛均为单细胞毛、非腺毛，上、下表皮细胞均为多边形，垂周壁呈深波状，气孔器均为平列型．这三个属的亲缘关系密切，应该归属于同一个大类群－蜡梅科。这为蜡梅属、夏蜡梅属、美国蜡梅属的分类提供了有用的性状特征。这三个属气孔器的演化趋势为：气孔器在保卫细胞的两极无"T"型加厚到有"T"型加厚，气孔器由单层外拱盖到双层外拱盖．

Epidermal features of the leaves of 5 species in 3 genera of Calycanthaceae wereobserved under light microscope and SEM. In species of genera Chimonanthus,Sinocalycanthus and Calycanthus, the leaf trichomes all are unicellular and nonglandular,the upper and lower epidermal cells have the same shape with sinuate anticlinal walls, andthe stomata are of paracytic type, which can be attributed to the same familyCalycanthaceae. The evolutionary trend of stomata in the three genera is recognized as theguard cells at polar regions from having no T-shaped thickening to having, and thestomatal rim at both sides being from one rim to double rim.