Woodcut Printing (HANGA) of Morning glories
Copyright 1998-2017 Yoshiaki Yoneda
Asagao, the morning glory, is thought to have been brought over from China as a Chinese medicine during the Nara era (710-784). At first it was called Kengo and its seed Kengosi (or Kenigosi), but eventually it came to be called the morning glory, as its beautiful flower opened early in the morning. The morning glory flower became a subject of aesthetic admiration. In the Edo era (1615-1868), the morning glory became loved broadly as a flower of the common people of Japan, and it appears in haiku, joururi (a kind of musical narrative), kabuki, and so on. The original blue flower was depicted in "Heike Noukyou" (a group of decorated scrolls of Buddhist sutra dedicated by the Taira family to the Itukusima Shrine (1164). A white flower seems to have appeared before the Edo era, but it was not documented until 1664. White, red, asagi (light blue), and azure flowers, as well as a dwarf morning glory called futaba asagao, were documented by the end of the 17th century. A black-and-white flecked flower (somewake) and a double flower are described in "Buturuihinsitu" (Collections of herbs and natural products) by Gennai Hiraga (1762, Houreki 12). Split, Swertia-like, and pear flowers are described in "Honzoukoumokukeimou" (Enlightening outline of natural materials for medicinal use) in 1803 (Kyouwa 3).
Cultivation of the varied morning glory boomed more than once during the latter Edo period. In the first boom, during the Bunka/Bunsei era (1804-1829) corresponding to the period of overripeness of Edo culture, many new mutants appeared. Morning glory specialty picture books, such as "Asagao-hinruizuko", "Kadan-asagao-tuu", " Asagaoso", and "Teityu-asagao-hu", were published from Bunka 12 (meaning the 12th year of the Bunka era, or 1815) to Bunka 14. The second boom was during the Kaei/Ansei era (1848-1860). In this period, new variants such as rangiku (polymorphic), rinpuu (brown) and swallow (miniature) appeared, and the main trend in cultivation was to combine many already-existing mutants with the botan flower, which is a kind of double flower consisting of petalled stamens and pistils. The varied flowers of the Japanese morning glory became still more intricate and splendorous. Especially, the novel flowers saizaki, sisizaki (lion or feathered) and daizaki (daizaki or cup flower) combined with botan (double flower) were depicted in special picture books, such as "Santo-ittyo" and "Asagao 36 kasen" published in Kaei 7 (1854), and "Tohi-syuukyou" published in Ansei 4 (1857). In addition to these, of course, other variants were combined, and so compound flowers with strange leaves were cultivated. Such endlessly variable characteristics were most suitable for the name of the varied Japanese morning glory.
Old picture books of the morning glory (from the Edo era).
- Shoukiti Minegisi Asagao-hinruizuko (An illustrated monograph of the Japanese morning glory) Bunka 12 (1815).
- Kotendousyuzin Kadan-asagao-tuu (authority on flower bed of the Japanese morning glory) Bunka 12 (1815).
- Keiei Sizian Asagaoso (Varieties of the Japanese morning glory) Bunka 14 (1817).
- Ryuuhu Minegisi Asagao-hin (Varieties of the Japanese morning glory) Bunka 14 (1817).
- Sougiku Syuusui Teityu-asagao-hu Bunka 15 (1818).
- Sougiku Syuusui Asagao-mizukagami Bunsei 1(1818).
- Kyouyoukan and Bankaen Yokoyama Asagao 36 kasen (36 varieties of the Japanese morning glory), Kaei 7 (1854).
- Yosisuke Kou and Tomezirou Naritaya Santo-ittyo (Celebrated flowers of three cities), Kaei 7 (1854).
- Yosisuke Kou and Tomezirou Naritaya Ryotisyu (Rare varieties of the Japanese morning glory from 2 cities) Ansei 2 (1855).
- Yosisuke Kou and Tomezirou Naritaya Tohi-syuukyou (Rare varieties of the Japanese morning glory grown in the cities and countries) Ansei 4 (1857).
Commentary books of varied morning glory of the Edo era
- Yoshitaka Watanabe Varied Japanese morning glory (1984) Nippon Television Network
- Seizou Kasiwaoka and Mikinori Ogisu (ed.) Traditional gardening plants and the culture illustrated by pictures (1997) Abokkusha Pub. Comp.
- Yoshiaki Yoneda Varied Japanese morning glory -pursuit of gardening beauty in the Edo era- In: Culture journal of form  Flower and Blooming beauty p.29 (1999) Kousakusha Publ. Comp.