Shin Joon Hwan, an ecologist, walked along a road lined with cherry trees on the verge of blooming last week, examining the fine hairs around their dark red buds.
The flowers in Gyeongju, South Korea, an ancient capital, belong to a common Japanese variety called the Yoshino, or Tokyo cherry. Mr. Shin’s advocacy group wants to replace those trees with a kind that it insists is native to South Korea, called the king cherry.
“These are Japanese trees that are growing here, in the land of our ancestors,” said Mr. Shin, 67, a former director of South Korea’s national arboretum.
Mr. Shin’s nascent project, with a few dozen members, is the latest wrinkle in a complex debate over the origins of South Korea’s cherry trees. The science has been entangled with more than a century of nationalist propaganda and genetic evolution.
Cherry blossoms, celebrated by poets as symbols of impermanence, occupy a major place in Japanese culture. In medieval times they were associated with elite warriors, the “flower among flowers,” said Emiko Ohnuki-Tierney, an anthropologist who has written about the cherry tree.
During the Edo period, which began in the 17th century, the blossoms were nationalized as a symbol of Japanese identity, she said. And propagandists in Japan’s 20th-century military government compared killed soldiers to falling cherry petals, saying they had died after a “brief but beautiful life.”
During Japan’s rule over the Korean Peninsula, from 1910 to 1945, Yoshinos were planted as part of an effort to instill “cultural refinement” in colonial subjects, said David Fedman, the author of “Seeds of Control,” a 2020 book about Japanese forestry in colonial Korea.
Yoshinos have been intertwined with the thorny politics of colonialism ever since. South Koreans have occasionally cut them down in protest. And some argue that Yoshinos, which Japanese officials also sent to the United States in the early 1900s, should be replaced with king cherries — distinguishable by the lack of hair on their buds — claiming the latter are more Korean.
The politics of cherry trees have ebbed and flowed along with Japanese-Korean relations, and nationalist claims about them have mostly crowded out scientific nuances, said Professor Fedman, who teaches history at the University of California, Irvine.
“Even the genetics look complicated, and don’t give us the easy answers that we’re looking for,” he said.
Mr. Shin’s project is a reaction to decisions made by the Japanese authorities more than a century ago.
In the early 1900s, Japanese scientists described king cherries, found on Jeju Island, south of the Korean Peninsula, as the parent of the Yoshino. The claim that Yoshinos originated on Jeju then motivated South Koreans to spread them throughout the country in the 1960s.
Scientists have since debunked that theory. But another — that king cherries are Korean — lives on.
The theory has its own critics.
Wybe Kuitert, a retired professor of environmental studies at Seoul National University, said that “king cherry” refers to a set of hybrids, not a species with a geographically defined habitat. He characterized efforts by Korean scientists to pinpoint a “correct,” or original, king cherry species as misguided.
“In such a mess of hybrids, which is the correct one?” he said. “You don’t know. You can’t decide it by genomic sequences or DNA sampling.”
But Seung-Chul Kim, an American plant taxonomist at Sungkyunkwan University in South Korea, whose cherry research has been funded partly by the government, said the initiative to replace Yoshinos was worthwhile. Even if the evolutionary trajectory of king cherries is unclear, he said, they evolved independently on Jeju.
Only about 200 king cherries grow naturally in South Korea, Mr. Shin said. His group aspires to replace all of the country’s Yoshinos by 2050, when they near the end of their roughly 60-year life span.
“Ultimately, I’d like to see Yoshino cherries go away,” said Jin-Oh Hyun, the group’s secretary general, a botanist who propagates king cherries in the central city of Jecheon. “But we need to replace them in stages, starting in areas that are the most meaningful.”
In 2022, the group surveyed the cherry trees lining a promenade near the National Assembly in Seoul that is thronged with visitors every cherry blossom season. And last year, it studied cherries in the southeastern port district of Jinhae, where a festival celebrating Yi Sun-shin, a Korean admiral who helped repel a 16th-century Japanese invasion, is held every spring.
The trees in both places were predominantly Yoshinos, the group found.
When Mr. Shin surveyed cherry trees in Gyeongju last week, the landscape included pines, bamboos, pansies, plums and a 400-year-old zelkova tree. But the cherries, which had not yet bloomed, consumed him.
“It would be great if people around the world could enjoy both the Korean and the Japanese trees,” he said, adding that the distinction was not widely known. “But things are one-sided now.”
Two arborists in Japan said that they respected South Korean efforts to replace Yoshinos.
“Cherry trees alone have no meaning,” said one, Nobuyuki Asada, the secretary general of the Japan Cherry Blossom Association. “That depends on how people choose to see and manage them.”
