臺灣新歸化植物──大紅花野牽牛（旋花科）

Ipomoea cordatotriloba Dennst. (Convolvulaceae), a newly naturalized plant in Taiwan

在臺灣的旋花科中，以牽牛花屬有最多的歸化物種。近年於臺灣北部和中部低海拔開闊地又發現一歸化植物-大紅花野牽牛(Ipomoea cordatotriloba Dennst.)，本種的花冠直徑2.5 cm明顯大於其近似種紅花野牽牛(I. triloba L.)之1.5 cm，及擬紅花野牽牛(I. leucantha Jacq.)之2 cm，因此可與兩者明顯區別。本文提供大紅花野牽牛之特徵描述、彩色照片、線繪圖、近似種之比較照片及比較表，以供鑑定參考。

In the family Convolvulaceae, the genus Ipomoea has the most naturalized species in Taiwan. A newly naturalized species, I. cordatotriloba Dennst., was discovered naturalized at low-altitude open ground areas in northern and central Taiwan. The corolla diameter is larger in I. cordatotriloba (2.5 cm) than in the similar species I. triloba (1.5 cm) and I. leucantha (2 cm); therefore, these species can be easily distinguished. The taxonomic description, color photographs, and line drawings of I. cordatotriloba and the Chinese names and key for the similar species are provided to facilitate identification.