中文摘要
一、研究緣起
梅山口鐵線蕨為台灣特有種蕨類植物之一，目前僅知分布在高雄縣梅蘭林道，族群數量約有一百株。由於分布侷限，數量稀少，極待有效的保育。本研究探討其分類地位、生殖方式、及可能的親源關係，以提供保育參考。
二、研究方法及過程
梅山口鐵線蕨與其相似種作形態上的比較，並予以學名之合法化及形態描述，透過人工繁殖確認其配子體世代的發育，最後，由葉綠體DNA鑑定其母系親本為何物種。
三、重要發現
本種與鞭葉鐵線蕨、馬來鐵線蕨、及與半月型鐵線蕨外部形態相似，但仍可由植株毛被物、羽片羽柄長度、鱗片形態等細微特徵與本種區別。目前並未發現梅山口鐵線蕨具有正常發育孢子，且孢子不具發芽能力，族群須靠葉先端不定芽進行營養繁殖，推測梅山口鐵線蕨可能為一天然雜交種。另外由葉綠體DNA資料得知其母系親本可能是鞭葉鐵線蕨。由於過去本種學名並未合法發表，本研究於執行期間，正式提出將梅山口鐵線蕨命名合法化。
四、主要建議事項
本種正式名稱之合法化為玉山國家公園管理處提供植物分類上之解說教育實例。本種推測為天然雜交種，提供後續演化研究的重要材料；由於分佈過於侷限狹，數量過少，建議管理處隱匿分佈地點，以免有心人士前往採摘而致滅絕；區外保育則是另一刻不容緩之事。
英文摘要
Motive Adiantum meishanianum Liu et Chiou is an endemic and threatened fern in Taiwan, distributing strictly on the Meilan forest road, Kaoshsiung County, Taiwan. There are only about 100 plants in this population. Due to its limited distribution and small population, conservation of this species is urgent. This study explored its taxonomic status, reproductive modes, and possible phylogeny to provide useful information for further conservation. Method and Process Compare the morphology among this species and its allied species, including A. caudatum, A. malesianum, and A. philippense. Explore the reproductive mode of Adiantum meishanianum and trace its maternal species based on cpDNA data. Important finding Trichomes, the length of petiole of pinna, and the margin of scale are reliable characteristics to distinguish A. meishaninanum from its allied species. A. meishanianum does not produce normal spore and reproduce asexually by vegetative buds of fronds. It is suggested that A. meishanianum may be a natural hybrid based on its abortive spores and reproductive mode. In addition, the maternal species is suggested to be A. caudatum based on cpDNA. During this study, the name of Adiantum meishanianum has been validated. Suggestion This species provides an effective education material in terms of the plant taxonomy. This presumed natural hybrid also offers a suitable material for further study of fern evolution. However, the restricted distribution and small population make its severe situation of existence. To protect it in situ, the site of its population is better not published. In addition, conservation ex situ is needed immediately.
