摘 要 ：本文讨论了产于中国台湾省的台东苏铁(Cycas taitungensis)和产于四川省的攀枝花苏铁 (C. panzhihuaensis)的两个天然群落，比较了两者的地理位置、地质、古地理环境、生境、群落的植物种类组成及其两者的相关性。
我们认为：
1．两个群落分别位于中国东部与西部，相距遥远，分布区虽均位于中国亚热带常绿阔叶林区，但植物组成分别属于东部湿润与西部半湿润亚区，前者系中国一日本区系成份，与大陆东南沿海关系密切，并结合形态特征及地质与古地理环境推论台东苏铁与产于广东的广东苏铁(C. taiwaniana Carruth.) 、海南苏铁(C. hainanensis C.J．Chen)以及贵州苏铁(C.guizhouensis Lan et R.F. Zou)可能是同一种群的地理种; 而后者属中国—喜马拉雅区系。两地的苏铁群落有共同区系起源，后在各自地理环境下分化;
2．两地山脉均为南北走向，有利于在冰川时期植物的迁移与保存;
3．两地群落均为次生性，具有多岩瘠薄的相似生境，其相似性可能是残遗植物在生存竞争中更多依赖于不利的生境。
Abstract:This paper deals with the geographical position, geological and paleogeographical environment, habitat, species composition and relationship of two natural cycad communities from China, i.e. Cycas taitungensis community in Taiwan, and Cycas panzhihuaensis community in Sichuan.
We think that:
1.The two communities are located distantly in east and west parts of China. Though they are located in subtropical evergreen broad-leaved foreet region of China, they belong to east moist and west dry subregion, respectively. The majority of the species composition of the former community is of Sino-Japanese elements, indicating close relationehip with southeast coast region of mainland China. Accordingly it is presumed that C. taitungensis and C. taiwaniana from Guangdong, C. hainanensis, and C. guizhouensis form geographical species in a species group. While the species in C. panzhihuaensis community floristically consist of mainly Sino-Himalayan elements, with earlier origin. These two communities have common origin but differentiated in separate natural conditions.
2. Geomorphologically the mountains in the two places are north-south orientated, and are advantageous to the migration and conservation of plants during glaciation time.
3. These two communities are of secondary origin. With similar habitat of stony and barren soil. Their similarities are possibly the dependence of relic plants on unfavourable habitat in struggle for existence.