著者

若林 三千男

出版者

日本植物分類学会

雑誌

植物分類・地理 (ISSN:00016799)

巻号頁・発行日

vol.25, no.4, pp.136-153, 1973-03-30

被引用文献数

3

---

1) Thirteen Japanese species belonging to the genus Mitella (Saxifragaceae) are revised taxonomically with special reference to the morphology of flowers, the chromosome numbers, and their karyotypes. The distribution maps of all the Japanese species are given in Figs. 19-20. 2) The variation in the division of the petal was observed much greater than that reported previously even within a single species. There is a tendency of progressive reduction in the division of the petal usually in the basal portion of petal, and most extremely reduced ones are found in the apetalous flowers. This seems to be polytopic in occurrence, and any evolutionary trend can not be indicated only by this feature. 3) The chromosome numbers of Japanese species are shown in Table 2. The species with the superior ovary have 2n=14, and those with the inferior ovary 2n=28 or rarely 2n=42. 4) The karyotypes of Japanese species are shown in Figs. 4-18 and are summarized in Table 3. The two species with 2n=14 (M. nuda and M. integripetala) are distinct from each other in the karyotype and no close affinity can be found, and this is also supported from morphology. Among those with 2n=28, M. doiana, M. furusei, M. leiopetala, and M. stylosa have the chromosomes many in symmetrical form and less different in size within a single set, while the species having many asymmetrical chromosomes and those different in size within a single set are M. japonica and M. yoshinagae which are much more specialized than the formers in their karyotypes. The species morphologically specialized have not always the specialized karyotypes as seen in the case of M. doiana. 5) M. stylosa, M. furusei, M. leiopetala, M. makinoi and M. doiana are suggested to have close affinities to each other, and M. japonica, M. yoshinagae and M. kiushiana may also be speculated as that. M. pauciflora, M. acerina, and M. koshiensis remain further to be investigated, though these karyotypes resemble each other in appearance. 6) M. furusei seems to have an affinity to M. stylosa more closely than to M. koshiensis, and OHWI's proposal to reduce M. furusei to a variety of M. koshiensis should be rejected. The affinities among M. stylosa, M. leiopetala and M. makinoi are pointed out by OHWI and are supported by additional data given in this paper.