Pollen morphology of Sohmaea was newly described based on scanning and transmission electron microscopies (SEM and TEM). Pollen grains of S. diffusa, S. gracillima, S. laxiflora, S. teres and S. zonata were described and micrographed. Pollen morphology of S. diffusa was compared with S. laxiflora for the first time and the differences between both species were found in the sculpture at the mesocolpium and structure of the exine. Pollen grains of Sohmaea differ from those of Alysicarpus in colpus, exine and tectum in addition to the result of a previous paper (Ohashi et al. 2022).

A botanical inventory of the vascular plants of Iriomote Island, Japan, has confirmed the distribution of seven plant species, which were recorded in literature without any specimens. Additionally, we discovered new localities for ten endangered species that were previously known to occur only in limited areas on the island. The distribution and habitat of these 17 species within the island are provided with voucher specimens.

The fine structure of a benthic diatom Luticola tropica (Hustedt) Levkov, Metzeltin & A.Pavlov was examined using both light and electron microscopy. The following morphological features of this species are first revealed in detail through the present study. The areola is occluded by a hymen with perforations arranged in a regular scatter pattern. The mature cingulum consisting of four girdle bands, opens at one pole, divided into two types: a valvocopula with two rows of areolae, has a crenulated edge (pars interior) fitting on top of valve ribs; three copulae with ligulae are thinner than valvocopula.

Three noteworthy lichenicolous fungi were found on lichen thalli of Physcia caesia collected near Syowa Station in East Antarctica: Didymocyrtis epiphyscia and Tetramelas phaeophysciae are new to Antarctica, and Lichenostigma alpinum is new to East Antarctica.

Lecanorchis japonica Blume (Orchidaceae) is reported from Nepal for the first time.

Dr. Misao Tatewaki, former professor at Hokkaido University, occasionally described new intraspecific taxa in local floristic checklists without citing specimens in the protologue. In some cases he did not provide his new name or “Type” designation on the voucher specimens. Four intraspecific taxa, Viola mandshurica W.Becker var. crassa Tatew., Vi. selkirkii Pursh ex Goldie f. alba Tatew., Veronica schmidtiana Regel var. pubescens Tatew., and Ilex crenata Thunb. subsp. radicans (Nakai) Tatew. f. microphylla Tatew., were published during floristic studies of the Rebun and Rishiri islands, northern Hokkaido, Japan, in 1934 and 1941. In this paper, they are lectotypified from plausible original material in the herbarium of Hokkaido University Museum (SAPS).

We discovered Cephalanthera longifolia (L.) Fritsch (Orchidaceae) in Nagano Prefecture and C. erecta (Thunb.) Blume f. pelorica H.Hayak. & Suetsugu, a peloric mutant, in Nagano, Fukui, and Aichi Prefectures, Japan.