noun
A common annual weed with small blue flowers, native to East Asia. Scientific name: Commelina communis.
道端にツユクサが咲いていた。
Asiatic dayflowers were blooming by the roadside.
The name 露草 (dew plant) likely refers to the delicate flowers that open in the morning and wilt by midday, resembling dew. The exact historical derivation is uncertain.