The occurrence of seven species of thistles (genus Cirsium, Asteraceae) in the Oshima Peninsula, southern Hokkaido was confirmed. Cirsium kamtschaticum, C. grayanum and C. alpicola were dominant in the area studied. Cirsium kamtschaticum was abundant in the northernmost part of the peninsula. This species was replaced by the southerly distributed C. grayanum around the southern slopes of the Kariba Mountains. Between the distribution ranges of the two species, was a zone occupied by populations of thistles with unique conditions in the leaf base and stem pubescence, and conditions in floral characters intermediate between C. kamtschaticum and C. grayanum. In the southernmost part of the Oshima Peninsula, C. alpicola occurred sympatrically with C. grayanum. Four other species (C. pendulum, C. aomorense, C. pectinellum, C. yezoense) were not abundant, though not rare in the peninsula. They were often sympatric with either of the three dominant species.

The phenology of the three dominant species and two common species (C. aomorense and C. yezoense) was investigated with experimental transplantation at Hokkaido University, Sapporo. There was a considerable degree of phenological difference among these thistles.

To find useful characters contributing to clarify phylogenetic relationships among the species of Vicieae (Leguminosae), comparative morphology and anatomy of styles of the genera Lathyrus, Lens, Pisum and Vicia were studied. Eight types of styles in transectional outlines at the pollen brush region (when adaxial surfaces face downwards) were distinguished. These types are 1, circular; 2, dorsally compressed oval; 3, laterally compressed oval; 4, inverted triangular; 5, triangular with elongation of lateral sides; 6, dorsally compressed oval with elongation of lateral sides; 7, segmental (chard faces downwards) with elongation of lateral sides; and 8, V-shaped with elongated margins meeting abaxially. The inverted triangular type is presumed to be apomorphic against the circular type according to the out-group rule. This type was observed only in the species of Vicia which, at the same time, always has an abaxially tufted pollen brush. These Vicia species found to have otherﾊtwo apomorphic characters, i.e., a stylar canal runs through the extremely adaxial side in the pollen brush region against through almost central, and the style is club-shaped against tapered. These features may support monophyly of these Vicia species.

The fern genus Pyrrosia Mirbel is revised and enumerated for all the Asian species, as well as some species from neighbouring regions, with an artificial key to all the species recognized. Sixty-four species are distinguished in a rather splitted conception for further biosystematic analysis. Three species, Pyrrosia ensata, P. shennongensis, and P. fuohaiensis are new to science from China.

Two species of bark-inhabiting Chlorella were collected from the Uchibo area, Chiba Prefecture, Japan. One is ovoid in shape and the other is elongately ellipsoidal. The chloroplast of these two algae is basically identical and band-shaped with irregularly undulated margin. The pyrenoid structure is also almost the same in both algae. The pyrenoid is penetrated by thylakoids which irregularly undulate or encircle, and surrounded by many small starch grains. Pyrenoglobuli are found at the periphery of the pyrenoid and rarely around thylakoids. The autospores produced in the ovoid alga are unequal in size, while those of the elongately ellipsoidal alga are almost equal. The ovoid alga is identified as Ch. trebouxioides Puncochárová. The elongate alga is recognized as a new species Chlorella angusto ellipsoidea Hanagata & Chihara. (Continued from J. Jpn. Bot. 71: 310-316, 1996)

The increasing number of threatened species and the loss of biodiversity on earth are the most terrible crisis we are faced to at the moment. However, it is speculated here that there are species which must have diversified in the developed areas or under human influences. The fern species with agamosporous life cycle seem to be diversified, at least to some extent, in the man-made environments after the Neolithic Age. Origin and development of the agamosporous fern species are synthetically considered under a focus of the speciation under the influence of humans. Diversification in flora and fauna seems to be partly added in artificial environments probably through evolution in simple combination of mutations, although these agamosporous species are not quite natural and have strayed down blind allies of their evolutionary cources.

Frequency and morphological characters of the natural hybrids between Taraxacum platycarpum and T. officinale were examined in Aichi Prefecture, C. Honshu, Japan. More than 90 % of plants currently referred to “T. officinale” had alleles b or c of glutamate oxaloacetate transaminase (GOT) introduced from T. platycarpum. These hybrid plants were morphologically intermediate between T. platycarpum and pure T. officinale in the number of marginal hairs in outer involucral bract, the length of corniculate appendage on the apex of outer involucral bract, and the size of achene.

Viola rostrata var. crassifolia Hashimoto (nom. nud.) has affinity with V. faurieana W. Becker rather than V. rostrata Pursh. However, this plant differs from V. faurieana by having longer spur of corolla and smaller and not lustrous leaves. It is growing in rocky, not stony, places. Thus, it should be treated as a distinct species, and is named Viola awagatakensis Yamazaki, I. to & Ageishi.

Primula sorachina Miyabe & Tatewaki in Trans. Sapporo Nat. Hist. Soc. 13 (1): 2 (1933).

f. candida H. Nakai & H. Ohashi, f. nov. Corolla candido, cetera ut in typo.

Nom. jap.: Yukiiro-sorachi-kozakura.

Typus: Hokkaido. Hidaka subpraefect., Urakawa-cho, in scopulis humidis artificialibus. H. Nakai, 24 May 1996 (TUS)

Cypripedium guttatum Sw. in Acta Acad. Holm. 251 (1800); Komarov, Fl. Mansh. 1: 508 (1901); Schltr. in Fedde Repert. Beih. 4: 81 (1919); Nevski in Fl. USSR 4: 596 (1935); Luer, Nat. Orch. U. S. & Canada 66 (1975).

Compared with Cypripedium yatabeanum, two leaves somewhat distantly disposed at the stem, 17-20 mm apart; the lip shorter, 14-21-(-25) mm long; stalk of lip shorter, 4-5 mm long; petals not expanded at apex; flower color white with dark purplish pink spots.

Hab. Akita Pref., Oga Peninsula (R. Mochizuki 1735, SHIN 179986). Newly found in Japan.

Distr. Europe, W. & E. Siberia, Sachalin, N. E. China, N. Korea, Alaska, Canada.