The end of the Spring, flowers have changed from cherry blossoms and then azalea to iris. This flower has several types as Ayame(あやめ), Kakitsubata(かきつばた), and Hana-shobu(はなしょうぶ). All of them are very similar but the flowering time and the shape of leaf are subtly different.

• Ayame : the beginning of May / the leaf is thin
• Kakitsubata : the middle of May / the leaf is thick
• Hana-shobu : from the middle of May to the end of June/the veins of the leaf is clear

Incidentally, Shobu which we put in the bath in May 5^th (端午の節句Tango-no-sekku) is not the same plant as Hana-shobu.

Even we write Ayame or Shobu, the Chinese charactors are same like 菖蒲. However, for Kakitsubata, there are two types like “燕子花” and “杜若”. On the one hand, the famous painting made by Ogata Korin (尾形光琳), is titled “燕子花”, on the other hand for the No-play is titled “杜若”.

A long time ago, people used to dye cloth with the flower’s liquid so that it has been called Kakitsuke-hana(掻き付け花), and little by little the flower itself became called Kakitsubata. Both of the works, Korin’s painting and the No-play have the same origin in Tales of Ise (伊勢物語). In the chapter 9, the main character named Ariwara-no-Narihira (在原業平) leads for the East (東Azuma) from Kyoto, then when he arrives at Toyohashi, he stops off a place where is splendid view of iris being in bloom all over the field. Someone asks him to compose a poem with using five letters, “Ka-Ki-Tsu-Ba-Ta”. Narihira, who was famous poet in the capital made it:

Kakitsubata / Kitsutsunarenishi / Tsumashiareba / Harubarukinuru / Tabiwoshizoomou （かきつばた/きつつなれにし/つましあれば/はるばるきぬる/たびをしぞおもふ）

The meaning of this poem is

I have a beloved wife / familiar as the skirt / of a well-worn robe / and so this distant journeying/ fills my heart with grief

(wikipedia)

Thus, Japanese people are accustomed to expressing with unifying a changing of season with human feelings.