铃子香属的叶表皮微形态特征及其分类学意义

Leaf Epidermal Microfeatures of Chelonopsis (Lamiaceae: Lamioideae) and Its Taxonomical Significance

研究了铃子香属(Chelonopsis)及其近缘类群毛药花属(Bostrychanthera) 共 16 种植物在光镜和扫描电镜下叶表皮微形态特征。结果表明: 除等齿铃子组外,铃子香属其它种类的叶表皮细胞多为不规则形; 叶表皮细胞垂周壁式样可分为平直至弓形,深波状两种类型。所有种类的气孔器都只分布于下表皮且均为不规则型; 保卫细胞的形状在种间几无差别,气孔外拱盖内缘的纹饰也都近平滑,表现出了高度的一致性。角质膜有三种类型,即山脊状,长条状,具颗粒状或雪花状附属物。叶表皮细胞形态特征及角质膜类型为铃子香属内组、系或种的划分提供了重要证据。此外,两个亚属内气孔密度的不同可能与各自的生长环境有密切的关系。

Leaf epidermis of 16 species from Chelonopsis and its related taxa, Bostrychanthera deflexa, were examined under both light microscope and scanning electronic microscope. As a result, all species are characterized with irregu-lar leaf epidermis cells, except those of sect. Aequidens （ C. souliei, C. forrestii and C. albiflora）, which are nearly rectangular. Two kinds of anticlinal walls of adaxial epidermis cells can be distinguished： sinuous and straight-arched. Stomatal apparatuses, whose density varies in different species, can only be found in abaxial epidermis. Highly consistent in all examined species are the type of guard cells and the smooth inner margin of outer stomatal rim. What＇s more, three cuticular patterns are recognized： ridged, long striped, and with snow flaked or granulate appendages. Consequently, Characters of leaf epidermis in Chelonopsis, such as pattern of epidermal cell and cutic-ular ornamentation, are of great significance in understanding the relationships at both infrageneric and interspecific levels. In addition, density of stomatal apparatuses may be correlated with the habitat of some species in Chelonopsis.