Dayflower blue
Description
A blue dye extracted from the petals of the Commelina communis lily plant native to Asia. Dayflower is a hardy, herbaceous annual plant that sprawls along the ground like a vine, often rooting at the nodes. The flowers bloom only for a day, emerging one at a time. For centuries, Japanese farmers raised dayflowers as a crop and harvested the tiny blue petals to make blue dye. Called 'dewflowers' presumably because the flowers were picked just after dawn when the dew was still on them, the blue petals are crushed, then washed to release the colorant. The primary blue colorant, commelinin, can be extracted more efficiently in alcohol (such as ethanol or isopropyl) or by boiling the petals in water. The plant's chlorophyll should be kept away from the blue pigment to prevent a muddy brown color.
The plant is considered invasive in the United States and it is resistant to many herbicides.
- See also [Uemera Dye Archive (Tsuki kusa)]
Synonyms and Related Terms
tsuyukusa (Jap.); aigami (Jap.); commelinin; Commelina communis (Asiatic dayflower); Commelina virginica (Virginia dayflower); mouse ears
Physical and Chemical Properties
- Flowers contain commelinin, an anthocyanin complexed with magnesium ions (metalloanthocyanin)
- Leaves = alternate, narrowly ovate to lance-shaped
- Stamens = 3 on short stems (sterile) and 3 on long stems producing pollen
- Blooms = May-October
- The pH of the extraction liquid affects the color.
- The dye is water-soluble
- The color fades with exposure to light and moisture.
Colorant Extraction
The traditional Japanese method for extracting the colorant from the dayflower petals is grind them into a paste, then slowly add water to form a vivid blue liquid, followed by filtration to remove the solid plant material. This process isolates the commelinin, a metalloanthocyanin that consists of anthocyanin molecules and magnesium ions, which together create the vibrant blue color. The delicate, water-soluble pigment not stable and will begin to turn brown within a day if left in water, thus it is captured onto a thin absorbent paper (e.g., Japanese Kozo paper), then kept in a dry, dark location. The resulting dried paper, called aobanagami or aigami, effectively stabilizes the dye, which can be re-liquified for use by adding water.
Resources and Citations
- L. Young, 'How the Humble Asiatic Dayflower Revealed Clues to Blue Hues' Science Friday, 2021 Dayflower Blue Chemistry
- S.Shimoyama, Y.Noda, S.Katshuhara, "Non-Destructive Analysis of Ukiyo-E Prints" Dyes in History and Archaeology, No.15, Paper presented in Manchester England, Nov. 1996.
- R.Feller, M.Curran, C.Bailie, 'Identification of Traditional Organic Colorants Employed in Japanese Prints and Determination of their Rates of Fading', Japanese Woodblock Prints, Allen Memorial Art Museum, Oberlin College, Oberlin, 1984
- Shiho Sasaki, Elizabeth I. Coombs, 'Dayflower blue: its appearance and lightfastness in traditional Japanese prints' in "Scientific research on the pictorial arts of Asia:proceedings of the second Forbes Symposium at the Freer Gallery of Art, 2005" AATA Getty
- Missouri Department of Conservation: Common Dayflower