This was the morning glory (Asagao / Ipomoea / Pharbitus / Convolvulus) I was growing for a contest but the plant didn’t grow very fast this summer due to the many cloudy and rainy days at the beginning, so I didn’t enter my pot afterall. But I did get some great blooms. The plant should start dying down soon. School children grow the morning glory as part of their curriculum in first grade of elementary school. Click on the “slide” button to view more of my photos of morning glories.
The History of the Japanese Morning Glory
The morning glory, Ipomoea nil, was introduced to Japan from China, probably in the Nara era, according to descriptions found in ancient herbal documents.
When was the morning glory in Japan and China have been introduced to Europe? The European who observed Japanese plants precisely and drew their figures is Kaempfer, who stayed in Japan for two years from 1690. By his illustrations, representative plants of Japan were introduced to Europe. The fifth volume of Amoenitatum Exoticarum (Kaikoku-kikan), described after Kaempfer’s return to Europe, includes Catalogus Plantarum Japonicarum (Nihon-shokubutu-si) (1712), in which he made simple mention of a lot of Japanese plants. Kaempfer described one of the items he observed as “Kingo, vulgo Asagawo”, in the flower grass class. Although he had no illustrations of the plant, this item described the morning glory clearly, indicating that documentation of the morning glory had reached Europe by the beginning of the 18th century.
It is said that Kaempfer investigated Japanese plants referring to Kinmou-sui (1666), a catalog by Tekisai Nakamura in which the following explanation: “Kengo is a flower of Asagao. The name of its seed is Kengoshi. The name of its vine is Kuji-sou” – is found. Accompanying this description is an illustration of the morning glory climbing up and twisting around a fence. Kaempfer probably observed the morning glory by referring to this figure.
Linnaeus adopted a figure of the morning glory of Dillenius as a standard specimen of Convolvulus nil L. in the second edition of Species Plantarum (1763).
Subsequently Thunberg, a pupil of Linnaeus, visited Japan in 1775~1776. In his Flora Japonica (1784), he described vulgo asagawo or the Japanese morning glory in detail, giving it the name of Ipomoea triloba. Willdenow (1799) enlarged Linnaeus’s Species Plantarum, and cited the Ipomoea triloba of Thunberg under the heading of Convolvulus nil L. This seems to be the first reference to the Japanese morning glory with the academic name of Convolvulus nil L. in the literature. The Latin name chosen by Thunberg was changed to Ipomoea triloba L. by Keisuke Ito in his Taisei-shokubutu-meiso (1829).
Then A. Franchet and L. Savatier (1875), studying Japanese plants, called the Japanese morning glory Pharbitis triloba Miq. The same name, Pharbitis triloba, was assigned also by Yoshio Tanaka and Motoyosi Ono in Yuuyou-shokubutu-zusetu (1891). In the Meiji era, when Western learning entered Japan and botany was brought about, the academic name of the morning glory seems not to have been settled yet in Japan. As indicated above, the Japanese morning glory had several Latin names in Japan at first. Soon, however, Pharbitis nil (L.) Choisy was adopted in general.
In 1833, Choisy proposed the new genus Pharbitis, which has three carpels, and separated it from Ipomoea (four or two carpels). Under this system, the morning glory was designated Pharbitis nil (L.) Choisy. When this proposed use of Choisy entered into Japan, Tomitarou Makino first assigned the name Pharbitis nil Chois. to the Japanese morning glory in Zoutei Soumoku-zusetsu (1907-1913), as originally described by Yokusai Iinuma. The name Pharbitis nil Choisy was used in a lot of illustrated books edited by Michio Murakoshi. Since then, this academic name has been used broadly in Japan as well as in the floricultural world in general. Since his first edition (1925) of the Illustrated Flora of Japan, Makino used Pharbitis nil Chois. for the Japanese morning glory, except for Ipomoea nil Roth, which appeared in his 1940 edition.
However, the genus Pharbitis of Choisy was not supported internationally. After the Index Kewensis (1895), compiled by British taxonomists integrated all members of the Pharbitis genus into the Ipomoea genus, the international community stopped referring to the Pharbitis genus.
A committee for establishing a uniform plant nomenclature rule meets regularly regularly, and its results have been summarized as the International Code of Botanical Nomenclature. In this Code, Pharbitis is now preserved as a conserved generic name. For example, in Nihon no yaseishokubutsu (Wild flowers of Japan) (1981), an illustrated book of Japanese flora, the morning glory is classified in the genus Ipomoea. Online source.
On the other hand, the common morning glory, bred horticulturally in Europe and America, has been called Ipomoea purpurea (L.) Roth for a long time. In addition, the dawn flower is also considered to belong to genus Ipomoea.