Story behind the art of Kaoru Takaishi

27th Annual International

American Society of Botanical Artists and the Society of Illustrators

Mitaka Osawa Wasabi

Eutrema japonicum

Biodiversity is what makes Mitaka Osawa wasabi unique. Its uniqueness highlights a distinct form of DNA which differs from other commonly produced wasabi, such as Daruma and Mazuma. Nowadays, Daruma and Mazuma are cultivated both in Japan and western countries. Mitaka Osawa wasabi, however, is only produced in Mitaka, Tokyo, Japan. According to a DNA study by Dr. Kyoko Yamane, an associate professor of Gifu University, its female DNA matches the native one in Gifu, Japan, while the male DNA matches a cultivated but extinct species.

Mitaka Osawa wasabi’s shape, size and color are other elements that distinguish this plant from other wasabi. The direction of growth contributes to shaping Mitaka Osawa wasabi differently. The rhizome grows horizontally to the slope of the wasabi field, whereas the rhizomes of other varieties are upright. Also, the size differs significantly; the rhizome of Mitaka Osawa wasabi is up to 2” long and 3/4” wide. Other common ones are about 5” long and 1” wide, which is the reason for their widespread commercial use at present. Lastly, Mitaka Osawa wasabi has a beautiful reddish pink color at the bottom of the stem which can be observed in Mazuma as well, although Daruma has a green color.  

Mitaka Osawa wasabi is an endangered species due to the following reasons: urbanization and its reproduction strategy. 

Urbanization is inevitable in Osawa, Mitaka, a rural area of Edo, the former name of Tokyo. Mitaka Osawa wasabi had a geographical advantage when it was transported by a farmer, Sei-e-mon Minowa from Ise, Mie, the west of Japan, to Mitaka around 1820; Mitaka was closer to the fish market of Kanda and later Tsukiji. Mitaka wasabi quickly became popular in this location, because many sushi carts around the fish market needed a fair amount of wasabi every day. At this time, the southern land of Shizuoka was the primary area of wasabi cultivation, but it was far from Edo. 

Mitaka city, however, changed into a residential area as the population grew in Tokyo, with houses and roads, resulting in decreasing and insufficient water flow into the wasabi field. This caused a significant impact on cultivation of wasabi because it needs to be kept around 60°F throughout the year. 

Vegetative reproduction is another reason why Mitaka Osawa wasabi has become endangered. The research by Dr. Yamane shows that the rhizome of Mitaka Osawa wasabi belongs to just one rhizome, which is 200 years old at least. In consequence, Mitaka Osawa wasabi often fails to bloom, rarely makes pollen, and never produces seeds.

To preserve Mitaka Osawa wasabi, the Osawa conservation program started in 2009 after Mr. Minowa’s family donated the farmhouse and the field after six generations to Mitaka City. The project team studied the traditional method of cultivation which the Minowa family had used, but the process has been difficult because adventitious buds are not strong enough to grow any more. So, the project team regrettably decided, in 2023, to cultivate plant cells to maintain quality.

Along with these activities, Mitaka City offered a workshop of botanical painting of Mitaka Osawa wasabi. I was so thrilled to be part of this wonderful event as an instructor for the first time. I wanted to paint this plant in the workshop as an example to use both to explain the plant itself and to further develop my painting skills. In the workshop, most of the 12 participants were complete beginners, but they learned quickly about Mitaka Osawa Wasabi’s cultivation, uniqueness and history. Their artworks were excellent, based on detailed observation. The exhibition of their artworks ran at the old farmhouse for almost two months this spring. Audiences could see the paintings beside the wasabi field next to the farmhouse. It is a protected area, so observations closer were impossible, but the paintings encouraged audiences to learn about this plant. This probably helped the conservation program.  

I am very honored to know that the members of the Osawa conservation program, including Mitaka City, the Minowa family, and the director of the Edo Tokyo vegetable association who connected me to this plant, are very excited that my painting is in the 27th Annual International, as the first showing of Mitaka Osawa Wasabi abroad. I hope my painting will help their activities a bit, and Mitaka Osawa wasabi can be produced enough to be offered with soba noodles in the local restaurant.

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