日本産ヨメナ属における種の分化の細胞学的, 形態学的および地理学的研究 V.

ヨメナ Kalimeris yomena

抄録

1. Kalimeris yomena KITAMURA, a plant of the Compositae, was found to have a wide distribution in the Japanese islands covering almost entirely the total distribution area of K. indica (L.) SCHULZ BIP., K. Incisa DC. and K. pinnatifida (MAXIM.) KITAMURA. However, the ecological preference of K. yomena was different from that of the related species. Differences in altitudinal distribution were also found among K. yomena, K. incisa and K. pinnatifida.
2. Approximately 1000 clones of K. yomena were collected from 124 localities and used for morphological and cytological studies. There was moderate morphological variation among the clones of each population, but the interpopulation variation of geographical significence was not clearly recognized. Propagating by rhizomes, the size of the clones of K. yomena was generally much larger than those of the related species.
3. Chromosome number was counted in 944 clones. Almost all the clones were true or near heptaploids with 2n=63±2. The frequency of the true heptaploids with 2n=63 was 87.6%. Among the 63 chromosomes, seven were satellited ones and closely similar to each other in shape and size. The behaviour of chromosomes at meiosis was irregular, the typical configuration of chromosomes at metaphase I being 27_II+9_I.
4. Because K. yomena is so closely similar in external morphology to some of the related species, its status as a species has been doubted by some taxonomists. The results of the present investigation, however, suggest that K. yomena is a natural entity that rightly merits the status of a species.