中国蔷薇科绣线菊亚科的演化、分布——兼述世界绣线菊亚科植物的分布

绣线菊亚科是蔷薇科最原始的亚科，共有22属260余种， 包括常绿和落叶两大类群，前者是 原始类型。我国有8属100种，全都为落叶性。本文着重讨论中国各属的起源、演化和分布等 ，同时也概述全亚科植物在世界各植物区的分布等问题。绣线菊属Spiraea是该亚科落叶类群中最原始的属，它在早期发生趋异进化，衍生出形态各异而亲缘关系密切 的不同属，本文阐明了中国各属的系统位置和属间的亲缘关系。通过对我国各属地理分布的 分析对比，属的分布区可归纳为5个类型。对全球绣线菊亚科植物在世界各植物区中的属、种数统计表明，东亚区有8属105种，其中有96个特有种，是该亚科植物分布最多而又最集中 地区，具有在系统发育上处于各主要演化阶段的落叶类型，因此，东亚区是全球绣线菊亚科植 物的现代分布和分化中心，也是落叶类群发生和发展的关键地区。在北美洲，从马德雷区至落基山区一带分布着11属46种，均为特有种，显然北美洲西部也是该亚科植物的现代分布中心，但可能是第二分布中心。南美洲至今保存2个较古老的常绿属，即Quillaja和K ageneckia,基于此，南美洲可能是绣线菊亚科某些常绿属早期分化和发展的关键地区 。中国绣线菊亚科植物在东亚区占绝对优势，有8属82种，其中有62个特有种,分别占该区属 、种和 特有种数的100%、82%、和65%, 这些类群分布最密集地区是在中国喜马拉雅森林植物亚区 中的横断山脉地区和中国日本森林植物亚区的西部，这一带是中国绣线菊亚科的现代分布和多样性中心，很可能是某些属的发源地。由此看来，绣线菊亚科的落叶属可能起源于劳亚古陆。据化石记载，该亚科植物的起源时间可以追溯到白垩纪早白垩世。

THE EVOLUTION AND DISTRIBUTION OF SUBFAM.SPIRAEOIDEAE (ROSACEAE) OF CHINA,WITH SPECIAL REFERENCE TO DISTRIBUTION OF THE SUBFAMILY IN THE WORLD

The subfam. Spiraeoideae, consisting of 22 genera and more than 260 species in the world,is the most primitive subfamily of Rosaceae. It has developed into two groups, i. e. evergreen and deciduous ones, of which eight genera and 100 species in China are totally deciduous. In the present paper, the origin, evolution and distribution of the Chinese genera is discussed mainly, and the distribution of the whole subfamily in the floristic regions of the world is also mentioned. Based on evolutionary trends of morphological characters, Spiraea L. is considered as the most primitive genus in the deciduous group of subfam. Spiraeoideae , from which some genera are been derived, the systematic position and evolutionary relationships between different genera are elucidated in this paper. Through the analysis on the geographical distribution of the genera in China, the areal types may be divided as follows; (1) North Temperate Type: Spiraea, Physocarpus, Aruncus. (2) East Asian and North American Disjunct Type; Sorbaria. (3) Mediterranean, West Asian (or Central Asia) and East Asian Type- Sibiraea. (4) Temperate Asian Type- Exochorda. (5) East Asian Type: (a ) Sino-Himalayan Distribution Neillia; ( b ) Sino-Japan Distribution Stephanandra. After analysis of the distribution of subfam. Spiraeoideae in the world, it is shown that the Eastern Asiatic Region, being the richest in genera, species and endemic species of the world, is not only the center of distribution and differentiation, but also an important region for occurrence and development of some deciduous genera of this subfamily, while in North America, the Madrean Region and Rocky Mountain Region, genera, species and endemic species are abundant, which indicates that the western part of North America is also the distribution center of this subfamily at the present, but it may be the secondary center of distribution. It can be seen that the relatively primitive and evergreen genera, i. e. Quillaja and Kageneckia, are now confined to South America. The fact implies that the South America may be the region for early differentiation and development of the evergreen genera in Subfam. Spiraeoideae. The analysis of Chinese plants has shown that China has the most members of the subfamily in Eastern Asiatic Region, with eight genera, 82 species and 62 endemic species and that the maximum concentration is in western Sichuan, northwestern Yunnan and their adjacent areas. It is very obvious that the center of distribution and diversity of Subfam. Spiraeoideae in China lies in the Hengduan Mountain Region of Sino-Himalayan Forest Subkingdom and the western part of Sino-Japan Forest Subkingdom, where may be the birthplace of some genera in China. It may be considered that the deciduous genera of Subfam. Spiraeoideae might have originated in Laurasia. According to the fossil records, the time of origin of Subfam. Spiraeoideae dates back to the Lower Cretaceous.