The name “Utsugi” means “hollow tree” and is given due to its characteristic hollow trunk. It is said that the month in which Utsugi flowers bloom became known as “Uzuki” in the lunar calendar. By the way, the origin of the name “Uzuki” comes from the term “嫵之花 (Bu no Hana),” which means “a tree with beautiful flowers.” The name “Uno-hana” for tofu lees (okara) is also derived from the resemblance of its appearance to the white blossoms of Utsugi. The famous poem “Natsu wa Kinu (the spring comes)” also describes Uzuki flowers as pure white, which is the typical color for these flowers. There are various claims about the number of Uzuki flower species, ranging from 7 to 12, but the Uzuki flower in the photo is a type of Utsugi called Sarasa Utsugi. It is a double-flowered variety with white on the inside and reddish-purple on the outside. “Sarasa” refers to a colorful, patterned cotton cloth originating from India. Due to its hard material, Utsugi wood is used for nails in chests and small boxes, as well as for barrel spouts and flutes.

ウツギの名は「空木」の意味で、幹が中空であることからの命名であるとされています。そして、ウツギの花が咲く月だから旧暦の四月を「卯月」と呼ぶ様になったと言われています。ちなみに卯の花の名前の語源は「嫵之花」で「美しい花の咲く（木）」という意味です。豆腐のしぼりかす（おから）をウノハナと呼ぶのも、この白い小花の咲いている姿と似ているからです。有名な『夏は来ぬ』に歌われている卯の花も純白で、これが一般的な花色です。卯の花は７種とも12種とも言われていますが、写真の卯の花はサラサウツギと言うウツギの一種です。八重咲き品種で、花の内側が白色、外側が紅紫色をしています。サラサ(更紗)とは、インドを起源とする、美しい文様を持つ多色染めの木綿布のことです。ウツギは材質が堅いので、たんすや小箱の木釘に使われたり、樽の呑み口や笛にも利用されています。