The midsummer floral and autumnal fruit displays of goldenrain tree, Koel-reuteria paniculata, have caught the eye of Western botanists and gardeners alike since 1747, when Pierre d’Incarville, a Jesuit priest, introduced the species to Europe from northern China. By 1763, this charming tree was being grown in the Jardin du Roi in Paris, and in 1809 it made its first known appearance in the United States when Thomas Jefferson received a shipment of seeds from Madame de Tessé, a French aristocrat and fellow botany lover with whom he often traded plants. It has since become a popular garden ornamental and is much appreciated for its tolerance of urban conditions.Goldenrain tree’s Chinese distribution lies in the eastern half of temperate China, extending from Sichuan Province northeast to Liaoning Province, where it is frequently found growing in dry streambeds and valleys. About a dozen separate populations have been discovered on The (un)Natural and Cultural History of Korean Goldenrain TreeMichael S. Dosmann, Thomas H. Whitlow, and Kang Ho-DuckGoldenrain trees in bloom above their namesake restaurant—Mogamchoonamu—in Balsan 1-Ri, a fishing village near Pohang on the eastern coast of the Korean peninsula.ALL PHOTOGRAPHS, EXCEPT OTHERWISE INDICATED, ARE BY THE AUTHORS.the Korean peninsula as well as in Honshu, Japan. Several theories about the origin of these popula-tions have been proposed. The close proximity of most popula-tions to the Yellow Sea suggests a likely route for Chinese propa-gules dispersed by water, man, or some combination of the two. In his 1976 monograph of the ge-nus, Frederick Meyer of the U.S. National Arboretum states con-vincingly that the species’ appear-ance outside of China was due solely to man.1 The species was not encountered during Japanese botanist Takenoshin Nakai’s thor-ough survey of the Korean pen-insula (1915–1936).2 However, we cannot assume they were not present at the time, as the small, isolated populations could easily have been overlooked. Contrary to the view that the species was introduced from China, the recent discovery of several inland populations has led to speculation by some that it was once naturally widespread throughout the Korean peninsula and that only a few remnant populations remain.3The cultural significance of goldenrain tree in Asia lends support to the argument for human-mediated origins. Chow noted that in China it was common around temples, palaces, and gardens and was used to mark the tombs of important officials.4 Likewise in Japan, the use of goldenrain tree is linked to religious prac-tices. An early researcher posited that it may have first appeared in a Buddhist monastery in Kyoto around 1220 AD, grown from seeds brought from China.5 Ohwi, a prominent Jap-anese botanist of the twentieth century, also believed in the Buddhist connection, pointing out that the species had naturalized near tem-ples along the shoreline.6 (Buddhism arrived in Japan in the mid sixth century, most likely by way of Korea, where it can be traced back to the mid-to-late fourth century.) In Korea, the spe-cies has been preserved in local forests by vil-lagers for use in shelterbelt plantings to protect homesteads from salt spray.7Their origin is not the only aspect of the Japa-nese and Korean populations that has puzzled botanists. Their ability to survive the stressful conditions at the ocean’s edge has also been of interest. In 1979 the Morris Arboretum’s Paul Meyer collected from trees in Paengnipo (also known as Panjikol) on the west coast of South Korea. He described the population as “a dense scrubby thicket with few plants reaching more than two meters, the plants growing on sand dunes, just above the high tide level.”8 He depicted the site as “exposed to periods of sea water inundation, wind, drought and salt spray.” Their unusual character also prompted collec-tion by Arnold Arboretum botanists Richard Weaver and Stephen Spongberg in 1977.9Recent studies of Korean populations, most of which now have government protection because of their biological and cultural significance, have found high genetic differences among popula-tions but low levels of genetic diversity within them, suggesting local inbreeding and little gene flow between populations.10 To date, however, the comprehensive phylogenetic study that would be required to establish the relationships of all the Korean populations—as well as those of China and Japan—has not been undertaken.Red dots mark the five Koelreuteria paniculata populations the authors visited in South Korea. Locations, counterclockwise from top left: Anheung, Anmyondo, Wando, Pohang, and Woraksan.Koelreuteria 17The Urban Horticulture Institute (UHI) at Cornell University has been studying the goldenrain tree for several years, in particu-lar because of its tolerance of the stresses of urban landscapes. The UHI staff has assembled a diverse germplasm repository of living plants from Asia as well as from Western gardens, and has been conducting experiments in the field, greenhouse, and laboratory to better understand the species’ natural variation and its physiologi-cal response to varying environments. Asia’s coastal populations have been targeted to test hypotheses related to microevolution and adaptation to salt spray. However, results of ex situ experiments, no matter how compelling, are best viewed in light of the plant’s natural habitat. Therefore, during the summer of 2004 the three authors visited five populations of goldenrain tree in South Korea, one inland and four along the coast. In addition to describing the sites and the condition of the trees, we collected tissue for future molecular analyses, measured photosynthesis to assess plant per-formance using a portable gas-exchange system (LiCor 6400), and, when possible, interviewed local people.AnheungMichael and Tom arrived in South Korea on the evening of June 14, 2004, and met Kang the following morning. During the ninety-minute drive to Seoul, we discussed woody plants of mutual interest—in particular, mogamchoon-amu (the goldenrain tree). Once at Dongguk University, we toured Kang’s laboratory, readied our expedition supplies, and met his graduate The first sighting of goldenrain trees was outside several marina buildings on the island of Anheung.18 Arnoldia 64/1students, including Kim Tae-Young, who joined us on our trip.The next morning, we left for the province