本文描述分布於臺灣低海拔的新歸化禾草： 長穎星草(Cynodon nlemfuensis
Vanderyst)，及於中部低海拔地區尋獲的歸化禾草：指狀加拿草(Tripsacum dactyloides (L.)
L.)，並確認肯氏畫眉草(Eragrostis cumingii Steud.)分布於臺灣平原及低海拔地區。此
外，本文將恆春狗牙根學名Cynodon arcuatus 列為C. radiatus 之異名，並提供臺灣產狗
牙根屬 (Cynodon) 植物的檢索表。

Cynodon nlemfuensis Vanderyst has recently become naturalized in low elevations of Taiwan, and Tripsacum dactyloides (L.) L. established its population in low elevations, central Taiwan. The occurrence of Eragrostis cumingii Steud. in lowlands and low elevations in Taiwan was confirmed. We describe these three grasses new to the flora of Taiwan. Besides, we provide a key to species of Cynodon in Taiwan, and the treatment of C. arcuatus J. Presl ex C. Presl, as the synonym of C. radiatus Roth ex Roemer & Schultes.