A new orchid species, Dendrobium popaense T.Yukawa & Nob.Tanaka is described from Mt. Popa, central Myanmar. It is discriminated from the closely related D. bensoniae by its smaller size in perianth lobes, its higher ratio of the length of mentum to dorsal sepal, and its conspicuously papillate operculum. From D. jinghuanum, the new species is separable by its lack of purple floral pigmentation, its lemon-yellow disk of labellum, its smaller size in perianth lobes, its higher ratio of the length of mentum to dorsal sepal, and its short, erect stem.

Mycorrhizal fungi of Liparis krameri from eight localities covering most of its distribution area in Japan were analyzed. Most of the fungi isolated from L. krameri were identified as Tulasnella spp. (Tulasnellaceae) based on ITS sequences. Tulasnella isolates were obtained from all localities. The results suggested that Tulasnella was the main mycorrhizal partner of L. krameri. Molecular phylogeny showed that the Tulasnella partners were located in a specific clade in the genus, suggesting that L. krameri has high specificity for its mycorrhizal partner. The mycorrhizal partners of epiphytic L. truncata were different from those of terrestrial L. krameri despite belonging to the same clade. It is likely that mycorrhizal partners changed during their life-form evolution.

Eight flavonoids were isolated from the flowers of Kerria japonica and identified as kaempferol 3-O-rutinoside (1) and 3-O-robinobioside (2), quercetin 3-O-glucoside (3) and 3-O-galactoside (4), and isorhamnetin 3-O-glucoside (5), 3-O-galactoside (6), 3-O-rutinoside (7) and 3-O-robinobioside (8) by UV, LC-MS, acid hydrolysis, and HPLC and TLC comparisons with authentic samples. On the other hand, five flavonoids were isolated from the leaves of the species. Of these flavonoids, two were identified as pectolinarigenin 7-O-rutinoside (9) and vicenin-2 (13). Although other three flavonoids were characterized as pectolinarigenin 7-O-(acetylrutinosides) by UV, LC-MS, acid hydrolysis, and the comparison with chemical data of the literature.

Phenolic compounds in the leaves of Hedysarum vicioides, an alpine plant widely distributed in Japan, were surveyed. Four flavonol glycosides, quercetin 3-O-robinobioside, 3-O-rutinoside, 3-O-galactoside and 3-O-glucoside, and a xanthone glycoside, mangiferin were identified. Both types of phenolic compounds possess UV absorbing and antioxidant properties. The overall content of phenolic compounds decreased when the plants cultivated in a growth chamber and a glasshouse, compared to plants grown in their native habitat. Under cultivated conditions, the decrease of quercetin glycosides was particularly marked. Furthermore, we also extracted components from the specimens and compared the composition of the plant with that of another congeneric species distributed in Japan, and found the differences between the two species. We describe the chemotaxonomic and ecological significance of the isolated compounds.