臺灣植物誌之觀察（21）──台灣細辛屬（馬兜鈴科）

Notes on the Flora of Taiwan (21)-- The Genus Asarum L. (Aristolochiaceae)

以植物外部形態花粉形態，染色體數目及其核型作為分類特微，訂正台灣之細辛屬（Asarum）植物，總共確認六種，包括二種新種，其種類為薄葉細辛（A . caudigerum），鴛鴦湖細辛（A. crassusepalum），上花細辛（A. epigynum），下花細辛（A. hypogynum），大花細辛（A. macranthum），及太平山細辛（A . taipingshanianum）。其花粉粒無孔，或具4-6孔。染色體除上花細辛為2n= 12外，其餘種類皆為2n=24。本文將本屬已發表之染色體核型分為七型，而以大陸西南地區之染色體型最繁雜，故支持馬金雙於1990年提出大陸西南地區可能為本屬之起源中心說法。由於台灣細辛屬植物之染色體核型包含於華南地區者，本文認為台灣之細辛植物乃由華南地區分化而來。

The genus Asarum of Taiwan is revised on the bases of morphology, pollen features and karyotype analysis. Six species including two new ones are recognized, i.e. A. caudigerum Hance, A. crassusepalum S. F. Huang, T. H. Hsieh & T. C. Huang, sp. nov., A. epigynum Hayata, A. hypogynum Hayata, A. macranthum Hook.f. and A. tatpingshanianum S. F. Huang, T. H. Hsieh & T. C. Huang, sp. nov. These six species can also be identified by using the pollen features alone. The pollen grains are characterized by inaperturate or 4-6-colpoidate. The chromosome number is 2n=24 except A. epigynum with 2n=12. The evidences from different karyotypes and their geographical distribution data make it possible to reconfirm that the center of origin for this genus is South West China. It is also suggested that the plants of Asarum of Taiwan are derived from South China since their karyotypes are within the range of the South China.