Natural habitats and geographic distribution of diploid Lilium lancifolium in islands of the Bay of Kyunggi, Korea

Habitats and geographic distribution were investigated for diploid and triploid L. lancifolium grown in 16 islands of the Bay of Kyunggi, the western region of South Korea. Most of natural populations were found at the coastal areas in the islands: 103 (72.5%) of 142 natural populations inhabited in sea cliffs, 28 (18.4%) in beaches, and the remainder in forests, roadside, riverside, grassy slopes and gardens. Among 16 islands investigated, 13 islands located in the southern and central area of the bay were inhabited by diploid populations alone. Kanghwa-do, the nearest island to the mainland of South Korea, was inhabited by eight diploid and six triploid populations. Bakryung-do and Sochung-do, the northernmost islands in South Korea, were inhabited by triploid populations alone. Combined with previously demonstrated facts on ploidy distribution of L. lancifolium, the results suggest that diploid L. laucifolium is indigenous to the middle western to southern islands and coasts of the Korean Peninsula, and Kanghwa-do and the neighbor islands are approximate northern limit of the distribution of diploid L. lancifolium.