1. 2School of Biological Sciences, Washington State University, Pullman, Washington 99164–4236 USA;
2. 3Botanical Gardens, University of Tokyo, Hausan, Bunkyo‐ku, Tokyo 112‐0001, Japan;
3. 4Department of Biological Sciences, Idaho State University, Pocatello, Idaho 83209–8007 USA;
4. 5Department of Botany, Kyoto University, Sakyo‐ku, Kyoto‐shi, Kyoto 606‐8502, Japan; and
5. 6Makino Herbarium, Faculty of Science, Tokyo Metropolitan University, Minami‐Osawa, Hachioji‐shi, Tokyo 192‐0397, Japan