English: This map portrays the locations of all known instances of the flower contest myth, in which an usurper deity (usually the historical Gautama Buddha, founder of Buddhism, who in this myth is described as responsible for human suffering) cheats in a flower-growing contest and thus spreads evil into the island/country/world. The original source of the myth is unknown, but it is attested throughout the Ryukyus, the Korean Peninsula, and Buryatia, as well as among two major Mongol groups (Khalkha and Ordos) and among Han Chinese communities in Gansu and Shanxi. The oldest attestation of the myth is from 1616, in a treatise associated with a Shanxi-centered Chinese mystery religion. By the eighteenth century it was already found among the Buryats.

The Korean dots are from Kim Heonsun's Hanguk-ui Changse Sinhwa, 1994. The Ryukyuan, Mongol, and Buryat dots are from Manabu Waida's "The Flower Contest between Two Divine Rivals," 1991. The Chinese dots are from Lee Pyungrae's "Monggol changse sinhwa-ui kot-piugi gyeongjaeng iyagi-e daehan jonghap-jeok gochal," 2012. Some dots in Korea and the Ryukyus represent multiple different locations.

The source map is from https://upload.wikimedia.org/wikipedia/commons/2/25/East_Asia_area_blank_CJK.svg

Red: The gods involved are/are named after the Buddhas Maitreya and Shakyamuni. For all instances except the Ordos Mongols (red dot south of China-Mongolia border), Shakyamuni is the cheater. Among the Ordos Mongols, the Maitreya Buddha is the cheater, but this makes little sense and per Lee 2012 may be a misunderstanding by the Russian transcriber.

Orange: The gods involved are other Buddhist/Chinese figures. Among the Khalkha Mongols, the contest is between the good Vajrapani Boddhisattva and a minor Buddhist figure. Near Seoul (in a folktale, not a myth), the contest is between personifications of Confucianism and Buddhism, with Buddhism being the cheater.

Blue: The gods involved are indigenous.

Green: Potentially related myths among the Altai Tatars (Turkic) and trans-Baikal Tungus. The former have a myth about stealing a part of a flower, while the latter have a myth about a tree-growing contest without cheating involved.