新歸化的台灣禾草－－單序草

Polytrias indica (Houtt.) Veldkamp, a Newly Naturalized Grass in Taiwan

單序草（Polytria indica）是近年來在台灣南部新歸化的禾草，最早的標本館紀錄採自2002年。此屬與金茅屬關係密切，事實上單序草的標本常被誤認為是細稈金茅。然而我們可以根據單序草小穗的特殊排列方式來加以區別，單序草在花序軸的每個節上，長有2個無柄及1個有柄共3個小穗。本文增補此種為新歸化之台灣產禾本科植物，並提供其物種描述及手繪圖供鑑定參考。

A newly naturalized species, Polytrias indica (Houtt.) Veldkamp, was found in southern Taiwan with the earliest collection made in 2002. It is closely related to the genus Eulalia Kunth. Several specimens of P. indica in Taiwan's herbaria were misidentified as Eulalia leschenaultiana (Decne.) Ohwi. Nevertheless, P. indica is distinguishable by its unusual arrangement of three spikelets, two of which are sessile and one pedicellate on the node. This paper provides a description of this newly naturalized species with a line drawing for identification.