noun
evening primrose; fragrant evening primrose
Sense 1 is the general term for evening primrose; sense 2 specifies Oenothera stricta. Both are common plant names.
庭にマツヨイグサが咲いている。
Evening primroses are blooming in the garden.
待宵草は夕方に花を開く。
Evening primroses open their flowers in the evening.
Katakana spelling; usually written in kana.
待宵 (matsuyoi, 'waiting for the evening') + 草 (kusa, 'grass/plant'), referring to its evening-blooming habit.