臺灣及琉球山月桃複合群的分類研究

Abstract

山月桃 (Alpinia intermedia Gagn.) 及其相關類群 (A. chinensis Roscoe、A. kelungensis Hayata、A. oblongifolia Hayata及A. suishaensis Hayata) 分布在日本琉球群島、臺灣及中國大陸，為中低海拔常見中型草本植物。此一複合群由於類群間的特徵差異小，以致不同學者對於此複合群的分群迄無共識，有待更深入的研究。本研究針對台灣 (包括蘭嶼) 及琉球分布的山月桃複合群，透過詳盡的文獻考證、野外觀察、變異數分析、Tukey事後比較分析以及主成分分析等形質分析方法，探討此一複合群的分類問題。研究結果顯示，營養器官特徵在此類群中無法提供有效的分群結果，應以生殖構造作為重要判斷特徵。而在生殖構造中，則以雌雄蕊長度、唇瓣的大小以及唇瓣基部是否具短柄等為最重要的鑑別特徵。綜合統計分析及主成分分析的結果皆支持將日本琉球、臺灣與蘭嶼之本複合群植物分為「琉球+蘭嶼」以及「臺灣」兩群，而透過原始文獻及模式標本的考證，確認「琉球+蘭嶼」的物種學名為A. intermedia，「臺灣」的物種學名則應使用A. oblongifolia。Alpinia intermedia Gagn. and its related species (including A. chinensis Roscoe, A. kelungensis Hayata, A. oblongifolia Hayata and A. suishaensis Hayata) are distributed in Japan, Ryukyu Islands, Taiwan and mainland China. It is a common herb frequently found in forest and forest edge at low and middle elevation. The taxonomic treatments of A. intermedia complex has been controversial due to minor morphological differences delimiting subgroups with the complex, implying a great necessity to study this complex in detail. In this study, I used the methods of morphometric analysis such as one-way ANOVA, Tukey’s Honestly Significant Difference Test and principal component analysis (PCA), combining with field observation and literature review to untangle the problem of Alpinia intermedia complex in the Ryukyus and Taiwan. The results obtained from one-way ANOVA and Tukey compare analysis show that the reproductive characters, especially the length of stamens / pistil, the size of labellum, and the shape labellum being shortly unguiculate or sessile, instead of vegetative characters, are important characters to separate taxa within this complex. The statistical analysis and principal component analysis both support to separate this complex of Japan, Taiwan and Orchid Island into "The Ryukyus + Orchid Island" and "Taiwan" two groups. We concluded the names for "The Ryukyus+ Orchid island” speciesould be A. intermedia Gagnep, while for "Taiwan" species should be A. oblongifolia.