Japanese species of the lichen genus Pannaria were revised. A new species in the P. rubiginosa group, P. asahinae P.M.Jørg. was described. P. globuligera Hue and P. insularis P.M.Jørg. & Kashiw., sp. nov. in the P. lurida group were recognized. A key is given to the sorediate/isidiate taxa recognized at present. Only material of P. lurida from meridional Japan belongs to subsp. lurida, whereas that from Hokkaido and northern Honshu belongs to subsp. russellii (Tuck.) P.M.Jørg., though often containing pannarin. P. tavaresii P.M.Jørg. is recorded as new to Japan. The term gymnidium is introduced for the special ecorticate lobules found on P. globuligera and several other species of the Pannariaceae. All names are typified when necessary.

Ophiopogon confertifolius N. Tanaka is described as new from the Malay Peninsula, Thailand. This species resembles O. fooningensis F.T.Wang & L.K.Dai from Yunnan (China), but differs from it in the number of leaves, the relative length of bracts to flowers, and the colour of flowers. A new variety, O. platyphyllus Merr. & Chun var. hayatae N.Tanaka, is described from northern Vietnam. This variety differs from var. platyphyllus chiefly by the pedicels articulate in the upper part. No confirmatory evidence has been obtained for the spontaneous occurrence of O. japonicus (Thunb.) Ker Gawl. in southern Asia (excluding China). A key to the 17 species of this genus hitherto recognized in this series of research is provided.

A new species and a new form of the genus Aconitum subgenus Lycoctonum are described from Hokkaido, Japan. Aconitum mashikense, an endemic of the Mashike and the Kabato Mountains, central Hokkaido, is characterized by pedicels golden villose with rough-surfaced patent hairs and linear bracteoles situated near the base of the pedicels. Aconitum gigas f. bicolor characterized by two-tone sepals is reported from southern Hokkaido.

A new species, Mussaendopsis malayana Yamazaki, is dscribed from the Malay Peninsula. This is the fourth species in the genus.

Distribution of 31 popular plants (Tab. 1 and Figs. 2-16) in Yamaguchi Prefecture, Chugoku District, western Japan was surveyed (Fig. 1) in cooperation with local botanists. Reynoutria sachalinensis was not detected. Humulus japonicus and Portulaca oleracea were restricted to lowland. Macleaya cordata, Adenocaulon himalaicum and Kerria japonica were restricted to hill region. Youngia denticulata and Cayratia japonica occupied lowland with some advance into hill region.