主要原產於歐洲、北非、西亞的牻牛兒苗科植物－小花牻牛兒苗（Geranium pusillum L.），新歸化於台灣中部山區，為一年或二年生草本。小花牻牛兒苗與最近歸化於臺灣山區的柔毛牻牛兒苗形態相似，但是花較小，且果實表面粗糙具短毛而可區分。本文提供分類特徵描述，手繪圖，照片與檢索表以供區分鑑定。

Geranium pusillum L., an annual or biennial herb mainly native to Europe, northern Africa, and western Asia, has recently become naturalized in mountain regions of central Taiwan at about 1,800-2,300 m in elevation. This species is very similar to G. molle, which was also recently found to have become naturalized in Taiwan; however, the former has smaller flowers and scabrous fruits. In the present work, we provide a taxonomic description, an illustration, photographs, and scanning electron micrographs to facilitate identification. Furthermore, a key to the taxa of the genus Geranium in Taiwan is also provided.