大风子科的地理分布及其起源

本文以属为单位,将大风子科84个属划分为27个分布亚型,隶属于11个分布类型。在此基础上对本科植物的地理分布进行了分析,认为大风子科是一个典型的热带性质的且富于岛屿区系成分和与各地区联系广泛的类群;其现代分布中心在旧世界热带地区,特别是热带非洲。根据其地理分布分析,结合板块及大陆漂移学说理论,可推断大风子科起源于古南大陆,特别是热带非洲地区;其起源时间至少不迟于白垩纪末期或第三纪初期,这一点已得到了古植物学资料的证实。

THE DISTRIBUTION AND ORIGIN OF FLACOURTIACEAE

This paper deals with the distribution and origin of Flacourtiaccae. 84 genera are classified into 11 area patterns and 27 subpatterns. Based on the analysis on the area patterns above, floristic characteristics of this family have been found as follow: 1. Flacourtiaceae is a tropical family. There are 72 genera, 85.7% of the total for the family, occuring in both the old world and new world tropics, and only 12 genera in the temperate region. 2. Island floristic element is rich. 14 island endemic genera, 16.7% of the total, occur in some islands, such as Madagascar, Rounion, Philippines, Srilanka, Maleysia etc.. Some other genera in different continents also occur in some islands such as west Indies, Juan Fermandez, Madagascar, Malaysia etc..3. Old world tropics, especially tropical Africa is a distributional centre of this family. There are 58 genera in the old world, 21 genera in the new world, and 28 genera in tropical Africa, 14 genera in tropical Asia, and 1 genus, in Australia. 4. Area patterns are various (11 area patterns and 27 subpatterns), and widely connected with those of the adjoining areas. This family might be originated in antique southern continent, especially in tropical Africa. Antique northern continent has not any old and primitive endemic elements from Flacourtiaceae, and antique southern continent has many primitive genera such as Berberidopsis, Lindackeria, Erythrospermum etc., and tropical Africa has 28 endemic genera, many of which. such as Camptostylla, Dasylepis, Scottelia, Buchnerodendron, Caloncoba, Gra- ndidera, etc. are very old and primitive. The originated time might be early Tertiary or late Cretaceous. The genera such as Berberidopsis occuring in tropical southern America and Australia, Erythrospermum in tropical Asia and tropical Africa (Madagascar), Lindacheria in tropical America and tro- pical Africa etc. might serve as an indication that Flacourtiaceae is dispersed to different continents from antique southern continent before Tertiary period or late Cretaceous. These views are supported by Pollin fossil evidence.