广东蕨类植物区系的特点

THE CHARACTERISTICS OF PTERIDOPHYTE FLORA FROM GUANGDONG PROVINCE

摘要:

广东蕨类植物区系共有５６科１３９属４６４种，其中含有很多原始的类型及孑遗种．区系分析表明：①广东有３个单型科．９个单型属及４个木本属；②以热带至亚热带分布科为主，占３９．３％，另泛热带科占３３．９％，广布科占２１．４％．温带科仅占７．１％；③单种属和少种属占绝对优势．共占７７．０％．又以泛热带属（４１属）和热带至亚热带（４１属）占优势．共占５９．０％，此外亚热带属（３６属）亦占２５．９％，而温带属（１２属）和广布属（９属）较少；这种分布格局显示了热带区系成分向亚热带地区渗透和过渡的特点；④广东蕨类区系与广西（特别是东南部）最为相似，属相似性指标达０．８４，种的相似性系数亦达０．６２，广东与海南、湖南南部、福建、江西南部亦较相似，充分显示了华南蕨类植物区系的整体性．

Abstract:

The pteridophyte flora of Guangdong consists of 56 families, 139 genera and 464 species, among them primitive taxa or relic species are abundant. A detailed floristic analysis shows: ① The pteridophyte flora of Guangdons has 3 monotypic familiar, 9 monotypic genera and 4 woody genera. ② The tropical and subtropical families are dominant, which constitute 39. 3% of the total families, and the pantropic, the cosmopolitan and the temperate families being 33. 9%, 21. 4%, and 7. 1%, respectively. ③ The percentages of cosmopolitan, Pantropic, tropic-subtropic, subtropic and temperate genera in fern flora of Guangdong are 6. 5%, 29. 5%, 29. 5%, 25. 9 % and 8. 6%, respectively. Most genera are monotypic and oligotypic (77%). The above distribution pattern reveals the transitiveness of the elements from tropical to subtropical. ④ The pteridophyte flora of Guangdong is closely related to that of Guangxi (esp. in SE Guangxi), the index of genus similarity being 0. 84. and is also related to that of Hainan, S Hunan, Fujian and S Jiangxi, Showing an integrality of pteridophyte flora of S China.