海桑科的系统进化及地理分布

对海桑科植物的系统学进行了分析 ,并对海桑属的两个组进行了修订 ,即以柱头头状为主要特征的海桑组和柱头蘑菇状为主要特征的无瓣海桑组。结合海桑科海桑属植物的古孢粉学、细胞学以及古气候等资料 ,可以推论出海桑科植物的起源时间为早始新世 ,起源地点为特提斯海岸 ,3条可能的主要扩散途径是从起源中心向南沿着岛屿扩散到澳大利亚 ,向西扩散经过印度扩散至非洲 ,向北沿着海岸向日本散布。第四纪的冰川作用对海桑科植物的现代分布产生了重要的影响

Systematics and biogeography study on the family Sonneratiaceae

The two sections in the genus Sonneratia L. f. are amended basing on a detailed morphological study. Sect. Sonneratia is characterized by capitate stigmas, whereas sect. Pseudosonneratia has peltate stigmas. The timing and centre of the origin of the family, and its putative routes of dispersal are also discussed. After considering palaeo geography, palaeo climate and fossil distribution data, we can conclude that the Sonneratiaceae originated in the Tethyan region in the early Eocene. Three dispersal patterns are suggested: westwards to Africa via India; northwards to Japan along the coastline; and southwards to Australia via the Malayan archipelagos. The global glaciation, which occurred during the Quaternary period, also played an important role in creating the present distribution pattern of the family.