禾本科广义拂子茅属Calamagrostis Adans. s.l.是广布于全球温带和热带亚热带高山的一个大属, 常分为拂子茅属Calamagrostis Adans. s.s.和野青茅属Deyeuxia Beauv..对国产5种拂子茅属和26种、1变种野青茅属植物在光镜下进行了叶表皮特征的观察.发现广义拂子茅属植物的叶表皮特征为典型的狐茅型, 很多结构在种间有丰富的变异式样, 如脉间长细胞形状、大小和细胞壁的厚度与弯曲程度, 短细胞形状和分布式样, 硅质体形状和分布式样, 气孔形状和分布式样, 以及刺毛形态和分布式样等.在国产种类中首次发现微乳突结构, 在很多种类中发现刺毛硅质化现象.用UPGMA对15个叶表皮性状进行分析, 结果分为两大支: 具加厚的长细胞、密集分布的短细胞和(或)刺毛以及刺毛硅质化的种类聚为一支;具薄壁的长细胞、较稀疏的短细胞和(或)刺毛以及刺毛不发生硅质化的种类聚为另一支.这种分异与广义拂子茅属的属下系统相关性不大, 但与种的海拔分布有关.前一支的种类大多生长于高海拔(2600 m以上)地区, 而后一支的种类则大多生长在低海拔(2600 m以下)地区.%Calamagrostis Adans. s.l. is a genus with variable definition in which two genera are often recognized in China: Calamagrostis s.s. and Deyeuxia Beauv. In this study, the leaf epidermis of five species of Calamagrostis s.s. and 26 species and one variety of Deyeuxia was examined under light microscopy. Although all the species examined have a Festucoid type epidermis, a number of variations of some epidermal features exist at the species level. This includes variation in morphology and wall thickness of intercostal long cells, shape and distribution patterns of stomata, morphology and distribution patterns of short cells and silica bodies, morphology, silicification, and distribution of prickles, and presence of micropapillae. Fifteen qualitative characters of the leaf epidermis were used in a phenetic analysis. No sharp differences were found between Calamagrostis s.s. and Deyeuxia. However, there are two major clusters in the UPGMA tree. The first cluster includes species with thick-walled long cells, frequent short cells and/or prickles and silicified prickles. The second cluster includes species with thin-walled long cells, infrequent short cells and/or prickles and unsilicified prickles. The results show that leaf epidermal variation is related with environment, but not concordant with any of the infrageneric classifications of the genus. Species in the first cluster are usually distributed at an altitude above 2600 m, while those of the second cluster are generally distributed at an altitude below 2600 m.
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