马清温 李承森 李凤兰
摘 要 柳杉属是现存杉科植物中最原始的类群，仅日本柳杉1种和柳杉1变种。日本柳杉和柳杉的叶片与枝的夹角变化范围都比较广，在没有生殖结构的情况下，仅靠枝叶的形态特征和表皮的结构难以区分二者。表皮结构是区分杉科形态相近属的重要特征之一。日本柳杉和柳杉的叶片每个面都有气孔线，也有报道柳杉属叶片近轴面与远轴面的气孔带不同，柳杉属叶片近轴面的气孔带比远轴面的气孔带明显，这和台湾杉属植物叶片的气孔分布近似。除落羽杉属植物外，杉科多数植物的气孔长轴与叶片长轴平行，柳杉属植物气孔斜向排列在科杉是比较独特的一个特征。柳杉属植物与落羽杉属植物的气孔排列不同，落羽杉属植物的气孔长轴与叶片长轴垂直或斜向排列，斜向排列时，气孔长轴与叶片长轴的夹角>45°。柳杉属植物的气孔斜向排列，气孔长轴与叶片长轴的夹角一般<45°。现生植物的生存环境可以为同一植物类群内的化石植物的生存环境提供有用的信息。柳杉属植物分布在温带降水量比较高的地区，通常指示温暖潮湿的环境。
关键词 杉科 柳杉 表皮 气孔 生境
Epidermal Structures of Cryptomeria aponica and Implications to the Fossil Record
Ma Qingwen Li Chengsen Li Fenglan
Abstract Epidermal structures of the leaves from two varieties of Cryptomeria japonica D. Don, var. japonica occurred in Japan and var. sinensis distributed within south of China, were studied in the present paper. The results suggested that the two varieties would not be discriminated based on epidermal structures, but the epidermal structures could be used to identify the Cryptomeria from other genera in the family Taxodiaceae. The leaves are amphistomatic, the stomatal bands on the adaxial surface of leaves are more strongly developed than those on the abaxial surface in Cryptomeria, and they are generally the same as or less than those on the abaxial surface of leaves in the genera Sequoia, Metasequoia, Taxodium and Glyptostrobus, or sometimes there are no stoma on the adaxial surface of leaves in these genera. The oblique stomata of Cryptomeria are one of the particular features in the genera of the family Taxodiaceae, for the long axes of most stomata are parallel to that of leaves in other genera except for Taxodium and Glyptostrobus (scale leaves). The subsidiary cells of Cryptomeria are apparently distinguishable from those of Athrotaxis-type. The subsidiary cells of Metasequoia, Taxodium and Cunninghamia are more similar to those of Athrotaxis-type than other taxodiaceous genera. Fossil records of Cryptomeria were traced back to Lower Cretaceous and mainly found from Upper Cretaceous to Tertiary. The presence of Cryptomeria commonly reflects a warm climate with a permanently high degree of humidity.
Key words Taxodiaceae, Cryptomeria, leaf cuticle, stomata, habitats
Acta Palaeobotanica，2007,47(1): 281-289
