台灣赤箭屬植物分類研究

Abstract

本研究利用新鮮或乾燥材料之外部形態並佐以生態與生殖生物學調查資訊，針對台灣產赤箭屬（Gastrodia）植物進行分類研究。研究結果共確認19分類群，包含8新種分別為白赤箭（Gastrodia albida）、閉花赤箭（G. clausa）、擬八代赤箭（G. confusoides）、摺柱赤箭（G. flexistyla）、柳氏赤箭（G. leoui）、南投赤箭（G. nantoensis）、烏來赤箭（G. uraiensis）及台東赤箭（G. taitungensis），以及2新紀錄種緋赤箭（G. callosa）與日本赤箭（G. nipponica）。原先記載的八代赤箭（G. confusa）則排除台灣的分布。本研究並依外部形態將赤箭屬分為三個亞屬：赤箭亞屬（subg. Gastrodia）、珊瑚赤箭亞屬（subg. Corallogastrodia）以及小赤箭亞屬（subg. Demorchis）。結合花朵及營養器官的形態特徵可作為亞屬區分之依據；而花部形態，尤其是唇瓣與蕊柱形態是物種間區辨的重要依據。多數赤箭屬的物種生長於海拔1500 m以下之森林，且常出現於非原生環境。形態觀察與生殖生物學的調查結果顯示台灣的赤箭屬物種包含了不同傳粉機制的自花授粉及蟲媒花類群。傳粉模式的轉變可能是赤箭屬分化的重要影響因子。

The present study focuses on the taxonomy of the genus Gastrodia (Orchidaceae) in Taiwan. Based on morphology observation of both fresh and dry materials accompanying with investigation of ecology and reproductive biology, 19 Gastrodia taxa in Taiwan were recognized, including 8 new species (Gastrodia albida, G. clausa, G. confusoides, G. flexistyla, G. leoui, G. nantoensis, G. uraiensis, and G. taitungensis) and 2 new records (G. callosa and G. nipponica). The previously reported G. confusa was excluded from Taiwan. The genus Gastrodia was divided into 3 subgenus (subg. Gastrodia, subg. Corallogastrodia and subg. Demorchis) based on morphology characters. Both vegetative and reproductive characters were useful in infrageneric division. Floral characters, especially lip and column structure, are most important in the specific classification. Most Gastrodia species in Taiwan occur in forest below 1500 m altitude, and many populations were found within non-primitive vegetation. Results from morphology observation and reproductive investigation revealed that Gastrodia species in Taiwan contain insect-pollinated and self-pollinated taxa with various pollination mechanisms. Shifts of pollination patterns may play an important role on the differentiation and speciation of Gastrodia.