Two new species of Ranunculus (Ranunculaceae) are described from Japan. Ranunculus hasunumae Kadota is described from Kitakata-shi, Fukushima Pref., Honshu, central Japan. It is distinguished from R. repens L. in having 1) thick and lustrous leaves, 2) less divided leaf lobes, 3) deep purplish stem and petioles at base, 4) strongly hooked achene beaks, and 5) larger and heart-shaped scaly appendages of nectaries, and 6) longer, thicker, glabrous pedicels. Ranunculus hasunumae was found to occur along the margins of a planted Cryptomeria japonica grove. Ranunculus hondanus Kadota is reported from wooded marsh, Setana-cho, Kudō-gun, Hiyama Subpref., southwestern Hokkaido, northern Japan and is different from R. hakkodensis Nakai in having 1) decumbent and not prostrate stem, 2) larger flowers 12–15 mm in diam., 3) larger petals 7–8 mm long, 4) scaly appendages fused with nectaries, 5) larger fruiting heads 8–10 mm in diam. and 6) short-stalked achenes with apically hooked beaks 1.5 mm long.

To understand floral and reproductive nature of Guettarda speciosa L. (Rubiaceae) occurring in Taiwan and Japan, we investigated variation of stigma and anther heights, pollen stainability and size, compatibility system by artificial pollination experiments, and reproductive outputs in natural populations. Stigma and anther heights continuously varied among the individuals and did not show a bimodal distribution known in the typically distylous species. However, the separation between the stigma and anther heights and their orders indicated that this species was morphologically distylous with L- and S-styled morphs, although its stigma and anther heights were not reciprocal between the two morphs. These two morphs occurred in even ratio and set fruits with seeds equally in natural pollinations. Moreover, hand pollination experiments indicated that both morphs had self- and intramorphic incompatibilities, suggesting that cross-pollination between different morphs was significant for setting seeds. These results indicate that the examined populations of G. speciosa are also morphologically and functionally distylous and that the pollen flow is almost equal between the two morphs, irrespective of the fact that their stigma and anther heights lack the precise reciprocity.

The fine structure of a marine tube-dwelling diatom Berkeleya micans (Lyngbye) Grunow has been examined by light and electron (SEM and TEM) microscopies. The following morphological features of this species are revealed in detail through the present study. A branched colony which consists of several contiguous tubes; cells arranged in multiple rows in a tube; a linear or lanceolate valve with obtuse apices; external terminal and central raphe endings slightly turned in the same direction; internal terminal raphe endings with diminutive helictoglossae; striae consisted of rectangular areolae; perforated open bands consisted of three types.

Ramalina intestiniformis Kashiw. & K. H. Moon and R. sphaerophora Kashiw. & K. H. Moon (Ramalinaceae, Ascomycota) were found in Japan. Ramalina intestiniformis was found on Tsushima Island, Nagasaki Pref. and R. sphaerophora was found on Tsushima Island and in Yame-city, Fukuoka Pref. These are the first reports of each of the species from Japan.

A new natural hybrid of Arisaema (Araceae) from Shimokoshiki-shima Island, Kagoshima Pref., Japan, is reported. It shows morphologically intermediate characters between Arisaema japonicum Blume and A. ringens (Thunb.) Schott and is therefore recognized as a hybrid derivative of the two species.