わが国の各地をはじめ、朝鮮半島や中国、シベリアに分布しています。湿地に生え、高さは40〜80センチになります。5月から6月ごろ、青紫色の花を咲かせます。内花被片が細く直立すること、外花被片の中央部に白色の斑紋があることが特徴です。和名の語源は「書き付け花」、花汁をこすりつけて布を染めたことに由来します。中国語では「燕子花(yan zi hua)」と呼ばれます。
アヤメ科アヤメ属の多年草で、学名は Iris laevigata。英名は Water iris。
The Water iris (Iris laevigata) belongs to Iridaceae (the Iris family). It is a perennial herb that is distributed throughout Japan, as well as the Korean Peninsula, China and Siberia. This herb grows in marshes and can reach 40-80 cm in height. The bluish-purple flowers come in May to June. It is defined that the inner tepals are erect and the outer tepals have white mottles on the center. The Japanese name comes from the word "書き付け花" (scribble flower), which means that the flower juice was rubbed into the cloth to dye it. In Chinese, it is called "燕子花" (Yan Zi Hua).