KITAMURA (1954, 1955) pointed out that there are some corridors in the temperate zone on the southern side of the Himalayas through which the Sino-Jopanese element extended westwards their range and called them Himalayan corridor. The Himalayan corridor was discussed in the connection with Himalayan geology. 1) The vegetation of the north-facing slopes is rich in flora and different from that on the south-facing slopes in Himalayas. In general, in Nepal Himalayas, the corridors for the migration of Sino-Japanese elements are on moister northern slopes, whereas those for the western elements are on drier southern slopes. 2) A Himalayan corridor seemed to be established on the southern side of the Himalayan range in the Late Miocene when Cedrus invaded into Himalayas. There were some corridors on the both sides of the Great Himalayas in the Middle Pleistocene when the basic configuration of the Himalayas was formed. The corridor on Tibetan side which provided conditions for the migration of western elements existed up to the end of Pleistocene with the occurrence of Cedrus. 3) The corridor on Tibetan side disappeared due to the environmental deterioration caused by the upheaval of the Great Himalayas. The discontinuous distribution of Olea, Cotinus, etc. which are separated in West Himalayas and Southwest China can be explained by the extinction of Tibetan side corridor in the Late Pleistocene.

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The differentiation and history of H. middendorfii complex in Japan is suggested in this paper based on the geographical and ecological variations of the karyology with the C-banding method. Each interstitial C-band occurs in only the specific regions, respectively. The interstitial C-band on the long arm of the fifth pair of chromosomes occurs only in Hokkaido, that on the long arm of the eighth pair of chromosomes occurs only in Mt. Hakusan (2300 m alt.) and Takayama (600 m alt.) of Chubu district, that on the long arm of the ninth pair of chromosomes occurs only in the Kanto and Tohoku districts. The distributional range which each interstitial C-band shows suggests the very important facts on the differentiation and history H. middendorfii complex in Japan. It is inferred that the chromosomes having the interstitial C-bands have been formed by adding the part of the interstitial C-band. The range which the chromosome having each interstitial C-band appears seem to show the area which that has dispersed, and also to be to show the dispersal and migration of H. middendorfii complex in the respective regions since that occurs. The migration from lower cool temperate zone to subalpine zone in H. middendorfii complex seems to be relatively new phenomenon in the history of this species complex in Japan, probably after ice age. Since the eighth pair of chromosomes with the interstitial C-band on the long arm which show the most narrow range occur both in the subalpine zone of Mt. Hakusan and cool temperate zone of Takayama in Gifu Prefecture. Furthermore, the distributional range of each interstitial C-band suggests that the migration from lower cool temperate zone to subalpine zone or the occupations to the various habitats of H. middendorfii complex in Japan seem to occur independently in the respective regions.

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[in Japanese]

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Three new species of Poa having proliferating spikelets are described. All are endemic to Nepal Himalaya in elevation above 4400 m. In the genus Poa, as in other grasses, proliferation is characterised by the conversion of the spikelet, above the first two glumes, into a leafy shoot. Notes on the proleferating spikelets are given.

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[in Japanese]

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[in Japanese]

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Cirsium tashiroi and C. hidaense, which are closely related to each other, are distinguished from one another by the following characters: in the former, radical leaves sessile, incised or divided, cauline leaves subamplexicaul, involucres about 1 cm wide; in the latter, radical leaves long-petiolate, entire with spines on the margin, cauline leaves not amplexicaul, involucres 1.5 to 2 cm wide. However, many plants having intermediate forms have been observed in some natural populations. We investigated variation of these characters in their natural populations. The plants were collected with quadrat or line-transect method at the sites shown in Table 1. for analysis of radical leaf shape, leaf length (1), petiole length (p), width from the midrib to the margin in the widest part of the leaf (c) and width from the midrib to the margin in the most narrow part just above the part of c (d) (Fig. 1) were measured. For comparison of involucre size, length (a) and width (diameter in the widest part) (b) of the involucres were measured in the fresh heads (Fig. 1). Almost all plants had sessile or very short-petiolate and incised to devided radical-leaves (Cirsium tashiroi) in some populations had long-petiolate and serrate radical-leaves (C. hidaense) in the others, although a few plants might have the radical leaves which were divided in the lower part and serrate in the upper part (the intermediate forms) (Figs. 2, 4). The other populations contained all kinds of the plants (Fig. 4). Many upper cauline leaves on the plants with radical leaves of the intermediate forms and some highest leaves also on the plants of Cirsium hidaense were sessile and subamplexicaules. Distinctive correlation between the leaf shape and the size of the involucres was not recognized. And mean values of the size of involucres were variable among the populations (Table 2). The populations of Cirsium tashiroi are geographically distributed from Shiga Pref. eastwards to the western part of Shizuoka Pref., which is the same area as The Central Honshu defined by Kitamura (1934). Those of C. hidaense are distributed only eastern half of the Central Honshu. All populations investigated of the two species including intermediate forms are altitudinally distributed from 300 to 1100 m.

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Variations in gross morphology of Adenophora uryuensis MIYABE et TATEWAKI, an endemic species to Hokkaido, and its closely related species, A. pereskiifolia (FISCH. ex ROEM. et SCHULT.) FISCH. var. heterotricha (NAKAI) HARA here used in the sense of OHWI (1953) (including A. pereskiifolia (FIISCH. ex ROEM. et SCHULT.) FISCH. var. moiwana (NAKAI) HARA), which ranges from northern Honshu to Hokkaido in Japan, were investigated. These two species belong to the A. nikoensis complex characterized by glabrous cup-shaped disk, sessile cauline leaves, and thick roots. For fifty six plants from eleven populations (see Table 2, except for A. nikoensis populations), chromosome number were counted. The principal component analysis on the variations of eight morphological characters from nine populations of these two species and three populations of A. nikoensis in Central Honshu (see Table 1) were also conducted. Conspicuous differences in both external morphology and chromosome number were found between A. vryuensis and A. pereskiifolia var. heterotricha as follows; A. uryuensis MIYABE et TATEWAKI proved to be diploid with 2n=34 chromosomes, and is characterized by ovate or broad lanceolate calyx lobes, short disk (less than 1 mm in length), shorter style than corolla, and corolla lobes deeply dissected half as long as the total corolla length, whereas A. pereskiifolia var. heterotricha is a tetraploid with 2n=68 chromosomes, and is characterized by lanceolate or narrow lanceolate calyx lobes, cup-shaped disk (1-3 mm in length), longer style than corolla, and corolla lobes shallowly dissected, one third as long as the total corolla length. According to all the evidences available at present, it may be reasonable to regard Adenophora vryuensis as an independent species, as was originally proposed by MIYABE et TATEWAKI (1935). As stated above, karyological as well as morphological characteristics of this plant clearly reveal its status as a biological independent entity, and this plant is readily distinguishable from a wide-ranging species, A. pereskiifolia sensu lato.

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