noun
needle spikerush
A plant species (Eleocharis acicularis). Botanical term; typically written in katakana.
マツバイは水田や湿地に生える細い植物です。
Needle spikerush is a slender plant that grows in rice paddies and wetlands.
The name likely derives from the needle-like leaves resembling pine needles (松葉) and the rush-like appearance (藺).