A Taxonomic Study of Phyllanthus (Euphorbiaceae) in New Guinea

• Main Author: 張永聖
• Other Authors: 吳明洲
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/28361299197229723947

碩士 === 國立東華大學 === 生物資源與科技研究所 === 98 === Euphobiaceae, the sixth largest section of angiosperms, widely spread in the tropical and subtropical zones of the world, has 344 genera which contain more than 8000 taxa. Among which, Phyllanthus L. is subordinate to Fluggeinae of Phyllantheae of Phyllanthoideae. Containing 11 subgenus, 35 sections and 833 taxa, Phyllanthus L. is considered the largest genus of Phyllanthoideae. This study focuses on the pollen morphology of Phyllanthus in New Guinea and its suggested taxonomic reference. Pollen obtained from specimens were observed and photographed using Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM). The results show that there are eight pollen types, from the ancient type 3-syncolporate bireticulate, 4-colporate bireticulate, to the advanced 3-colporate reticulate, 3-syncolporate reticulate, 3-syncolporate vermiculate, Pantocolporate reticulate, to the most advanced pantoporate reticulate pollen. The exine structures of the pollen can be classified into three types: (Ⅰ) Tectate perforate type or complete tectate type, (Ⅱ) Incomplete tectate type, (Ⅲ) Intectate or etectate type. For Phyllanthus L. in New Guinea, it is proposed that pollen ornamentation can be a useful diagnostic tool for genus level. In addition aperturate type colporate can be treated as a critical feature for the level of section. Further, according to the traits of pollen ornamentation and its colporate, a temporal order of the subgenus evolution is proposed as following: Phyllanthus、Kirganelia、Gomphidium、Isocladus、Eriococcus. Based on this proposed order of evolution, this study also presents further observations on pollen stratification and inferences about evolutionary trends of exine strcture type. Morphological descriptions of 32 taxa in New Guinea, geographic elevation maps, notation and index for further research are included.