noun
wall iris; roof iris; Iris tectorum
A species of iris traditionally grown on thatched roofs in Japan; also known as fleur-de-lis in some contexts. Botanical name: Iris tectorum.
鳶尾は、昔から日本の家の屋根に植えられてきた花です。
The wall iris is a flower that has been planted on the roofs of Japanese houses since ancient times.
庭の隅に、紫色の鳶尾が咲いている。
Purple wall irises are blooming in the corner of the garden.
The name いちはつ is said to derive from the plant's early blooming period, literally meaning 'first to bloom' (一初). The kanji 鳶尾 (tobi-iri) is a later assignment based on the shape of the flower resembling a kite's tail.