A flowering plant (Orychophragmus violaceus) also known as オオアラセイトウ. The name ムラサキハナナ is the common Japanese name.
See also: オオアラセイトウ
In spring, Chinese violet cress blooms here and there in the park.
Katakana spelling is common for plant names and is the usual written form for this word.
Kanji spelling is rare; the word is usually written in kana.
From 紫 (murasaki, 'purple') + 花菜 (hanana, 'flowering vegetable/rape'), referring to the purple flowers and its resemblance to rapeseed flowers.