Commelina

...an annual plant of the Commelinaceae family (illustration) that commonly grows in slightly damp places on roadsides and wastelands. It is also called aobana or boushibana. In the past, it was called tsukikusa. The stem is 10-50 cm tall, the lower part is prostrate, and it branches out vigorously. The leaves are alternate, 5-7 cm long, egg-lanceolate, with a sharp tip, and prominent parallel veins. The base forms a membranous sheath that encases the stem. It produces blue-purple flowers from June to August. Several flowers are borne on short inflorescences wrapped in bracts, but they bloom one at a time, so they appear to be a single flower. The bracts are folded in two and tightly attached, and are either glabrous or hairy on both sides. ...

*Some of the terminology that mentions "Commelina" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…路傍や荒地のやや湿った場所にふつうに生えるツユクサ科の一年草（イラスト）。アオバナ，ボウシバナともいう。古くはツキクサと呼んだ。茎は高さ10～50cmで下部は倒伏し，盛んに枝を分かつ。葉は互生し，長さ5～7cm，卵状披針形で鋭尖頭，平行脈が著しい。基部は膜質の鞘（さや）となり茎をつつむ。6～8月に青紫色の花を咲かせる。花は苞葉に包まれた短い花序に数個つくが，1個ずつ咲くので一輪咲きに見える。苞葉は二つに折りたたまれてぴったりとくっつき，無毛または両側に毛がある。…

※「Commelina」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報