Osaka Metropolitan University and Kyoto University identify first new lily species native to Japan in 110 years — Growing in Honshu and Izu Islands

The Lilium maculatum-L. pensylvanicum complex of the genus Lilium in the family Liliaceae includes upward-facing, orange-flowered plants, for which four taxonomic groups have been recognized. The wild species and horticultural varieties created in Japan have been exported to other countries for more than 200 years. Because of this, their scientific names have often been described in overseas countries, and there are more than 100 scientific names given to plants in the Lilium maculatum-L. pensylvanicum complex. Moreover, the distinction of wild species largely remains ambiguous, and there have been a number of taxonomic challenges.

A research group led by Specially Appointed Assistant Professor Seita Watanabe of the Graduate School of Science at Osaka Metropolitan University, and Professor Minoru Tamura and Associate Professor Shizuka Fuse of the Graduate School of Science at Kyoto University analyzed the shapes and DNA of these Lilium maculatum-L. pensylvanicum complex and revised the conventional classification. The plants were classified into eight taxonomic groups. The group also discovered Lilium pacificum S. T. Watan., Fuse & M. N. Tamura, the first new Lilium species native to Japan in 110 years since Lilium nobilissimum was described by Dr. Tomitaro Makino in 1914. This plant grows on the coast of Honshu (Ibaraki prefecture to Shizuoka prefecture) and the Izu Islands, and has a unique characteristic of having the tips of its leaves curved into a claw-like shape. Of the eight newly recognized taxonomic groups (taxa), seven are endemic to Japan, have adapted to different environments from coastal to mountainous areas, and have evolved unique traits. These are believed to have differentiated through a complex process, and it is hoped that the findings of this study will provide clues for species differentiation research. The work was published online in TAXON.

Dr. Watanabe said, "Even in lilies with such prominent flowers, when you look at their morphology closely similarities and differences are revealed, and we were able to use the power of DNA to see the differences more clearly. Individual differences have been overlooked, perhaps because of the apparent simplicity of the plants. Through this research, I was reminded of the importance of morphological observation. We also had to look up a huge number of references written in various languages to determine the scientific names, which was also quite a chore."

Journal Information
Publication: TAXON
Title: Biosystematic studies on Lilium (Liliaceae) II. Evolutionary history and taxon recognition in the L. maculatum-L. pensylvanicum complex in Japan
DOI: 10.1002/tax.13141