A taxonomic study of Thymelaeaceae of Taiwan

本文利用外部形態、花粉外壁紋飾和分子序列等資料，對臺灣產瑞香科植物進行分類研 究。 根據以往的研究，花盤的形狀是區分瑞香屬與蕘花屬的重要特徵。結合本研究的結果，葉片的形狀與質地、苞片存在與否、花萼筒的顏色和解剖特徵、植株各部位的毛被情況等是臺灣瑞香科植物種間分類的主要依據。花粉外壁紋飾具有種間差異，可以提供部分的分類資訊。基於核ITS 序列構建的分子親緣關係在部分種類間具有解析力，也可以提供分類參考。 本研究將臺灣產瑞香科植物處理為二屬七種(含一變種):臺灣瑞香、芫花、白花瑞香、南嶺蕘花、披針葉蕘花、臺灣蕘花、烏來蕘花、倒卵葉蕘花；將以往研究中的矮瑞香、清水山瑞香、玉山瑞香和小瑞香處理為臺灣瑞香的同物異名；將原本的臺灣蕘花降為披針葉蕘花的變種；首次發現臺灣瑞香可能為雌花和兩性花同株植物，以及修訂以往名稱的誤用。This revision of Thymylaeaceae of Taiwan is based on morphological, palynological and molecular phylogenetic studies. According to former studies, the shape of disks is a key character to distinguish between the genera Daphne L. and Wikstroemia Endl. In this study, morphological features such as the shape and texture of leaves, the existence of bracts, the color and dissecting characters of calyx tube and the pubescence of the plant are useful in classification between species of Taiwan. Sculptures of pollen exine are with differences among species and give some comparative evidence. Molecular phylogenetic analysis based on nrITS sequences could also provide some taxonomic information in some taxa. In the present revision, eight taxa (including one variety) of two genera are recognized: D. arisanensis Hayata, D. genkwa Siebold & Zucc., D. kiusiana Miq. var. atrocaulis (Rehder) Maekawa, W. indica (L.) C.A. Meyer, W. lanceolata Merr. var. lanceolata, W. lanceolata Merr. var. taiwanensis (C.E. Chang) R.Y. Yu & J.M. Hu comb. nov. & stat. nov., W. mononectaria Hayata, and W. retusa A. Grey. Four former recognized species: Stellera formosana (Hayata) H.L. Li, D. chingshuishaniana S.S. Ying, D. morrisonensis C.E. Chang and D. nana Tagawa are treated as synonyms of D. arisanensis Hayata. The species W. taiwanensis C.E. Chang was reduced to be a variety of W. lanceolata Merr. Moreover, D. arisanensis is firstly reported to be gynomonoecious in this study. Some former mistakes on nomenclature are also revised.口試委員會申定書 ......... I 致谢 ......... II 摘要 ......... III Abstract ......... IV Content ......... V List of Figures ......... VII List of Tables ......... VIII 1. Introduction ......... 1 1.1 The family Thymelaeaceae ......... 1 1.2 The genera Daphne L. and Wikstroemia Endl. ......... 2 1.3 The research history of Thymelaeaceae in Taiwan ......... 6 1.4 Aims of this study ......... 9 2. Materials and Methods ......... 11 2.1 Materials ......... 11 2.2 Floral dissection ......... 12 2.3 SEM of pollen grains ......... 12 2.4 DNA extraction ......... 12 2.5 Polymerase chain reaction ......... 13 2.6 Sequencing and alignments ......... 14 2.7 Phylogenetic analysis ......... 14 3. Results ......... 16 3.1 Stem ......... 16 3.2 Leaf ......... 17 3.2.1 Leaf arrangement ......... 17 3.2.2 Leaf shape, apex and base ......... 17 3.2.3 Texture, venation and pubescence ......... 19 3.3 Flower ......... 23 3.3.1 Inflorescence ......... 23 3.3.2 Bract ......... 23 3.3.3 Calyx tube ......... 23 3.3.4 Androecium, Gynoecium and disk ......... 24 3.4 Exine ornamentation of pollen grains ......... 31 3.5 Fruit ......... 36 3.6 Molecular phylogenetic analysis ......... 36 4. Discussion ......... 39 4.1 Synonyms of Daphne arisanensis Hayata ......... 39 4.2 Sexual system of Daphne arisanensis Hayata ......... 43 4.3 The treatment of Daphne genkwa f. taitoensis (Hayata) Hamaya and the ascription of Daphne genkwa Siebold & Zucc. .......... 44 4.4 The differences between Wikstroemia lanceolata Merr. var. lanceolata and Wikstroemia lanceolata var. taiwanensis (C.E. Chang) R.Y. Yu & J.M. Hu ......... 45 4.5 Exclusion of Wikstroemia nutans Champ. ex Benth from Taiwan ......... 46 4.6 A cryptic species complex of Wikstroemia indica (L.) C.A Meyer ......... 47 4.7 Other revisions and notes ......... 47 4.8 Discussions on the concepts of species that are adopted by this study ......... 48 5. Taxonomic treatment ......... 52 Reference ......... 101 Appendix ......... 11