Biosystematics of Indo-Chinese Flora

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In June, 1994, K.Iwatsuki visited Paris Natural History Museum and investigated "Flora of Indo-China" based on the specimen deposited in their herbarium. During December, 1994 - January, 1995, K.Iwatsuki, N.Murakami and J.Yokoyama (assistant member of this project) visited Vietnam, Laos, and Thailand. Collaborating with C.Phengklai (Thailand), B.Svengsukusa (Laos) and N.N.Thin (Vietnam), we collected more than 2000 numbers of herbarium specimens and many DNA samples.This year, we got important results from our expedition to Northern Vietnam. This area is plant geographically important place, especially when we consider speciation of Japanese and Chinese plants. However, this area has not been well botanized and thus our expedition can contribute to great advances in understanding of the Flora and its evolutionary origin.For seed plants, we collected many specimen of Moraceae, Araceae, Rubiaceae, Cameliaceae and Compositae which had flowers and fruits in that season. We collected a new species of Arisaema (Araceae) from the mountain forest of Sapa. No related species to the new species have ever been collected in China, and thus is valuable when we consider speciation of Arisaema. Our study on these herbarium specimens are in progress.For ferns, we collected many specimens of Hymenasplenium and Neottopteris (Aspleniaceae). Both of the groups are very simple in morphology and hard to recognize the species. Therefore, we collected DNA samples as well as herbarium specimens from every localities where we found these plants, and made detailed comparison between them after we came back to Japan. We already determined nucleotide sequences of rbcL gene from some of these samples, and found several molecularly distinguishable taxonomic units. Further analyzes on our samples and specimen from Indo-China will lead us to deep understanding of the group.