Koji Takayama, Chie Tsutsumi, Dairo Kawaguchi, Hidetoshi Kato, Tomohisa Yukawa
Liparis hostifolia (Orchidaceae) on Minami-iwo-to Island in the Bonin (Ogasawara) Archipelago was rediscovered for the first time in 79 years during a field survey in 2017. Its identity was confirmed by morphological comparison and DNA extractions from herbarium specimens collected between 1914 and 1938. Results from the molecular phylogenetic analyses demonstrated that L. hostifolia belongs to the L. makinoana complex. In comparison with other members of the L. makinoana complex, the broadly ovate labellum, short dormancy period, and flowering from November to March are unique characteristics of L. hostifolia. Results from the molecular phylogenetic analyses also suggested that L. hostifolia has had a long-isolated history in the Bonin Archipelago and probably migrated from temperate East Asia.
Yukihiro H. Kobayashi, Shizuka Fuse, Minoru N. Tamura
To evaluate the evolutionary relationships among species of Peperomia subg. Micropiper, a phylogenetic analysis based on the DNA sequences of plastid regions atpB-rbcL, psbK-I, rpL16, rpS16, trnG, trnK (including matK), trnL-L-F, and trnS-G was conducted using 20 species, in addition to four outgroup species. The trnK sequences of 46 species and trnL-L-F sequence of one species were quoted from GenBank and also included in the analysis. The results showed that P. subg. Micropiper includes seven major clades, which are also supported by morphological characteristics. They are recognized as sectionequivalent plant groups, namely Alatoid, Blandoid, Glabelloid, Glaucoid, Japonicoid, Lanceolatoid, and Rotundifolioid. A chromosome analysis of the subgenus yielded nine new counts: 2n = 22 (diploid) for P. alata, P. bicolor, P. diaphanoides, P. flexicaulis, P. hylophila, P. polystachya and P. prosterata, 2n = 44(tetraploid) for P. okinawensis and 2n = 132 (dodecaploid) for P. reticulata. Japonicoid, which occurs outside the Americas, i.e. in Asia, Africa, and the Pacific islands, is tetraploid, decaploid, and dodecaploid (not diploid), while the remaining six plant groups are native to the Americas and diploid (except Glaucoid, which is tetraploid). Further, P. diaphanoides is conspecific with P. glabella. Peperomia boninsimensis from the Ogasawara Islands, Japan, is more closely related to Polynesian species than to other Japanese species. Peperomia okinawensis should be regarded as a variety of P. japonica.
The Dryopteris varia complex (subg. Erythrovariae sect. Variae Fraser-Jenk.) is an apogamous fern complex. Most species of the complex are triploid apogamous, show morphological and genetic variation, and present difficulties in their identification. Recent molecular research suggested that the reason that each apogamous species in the complex is so variable is due to reticulate evolution through hybridization between diploid sexual and triploid apogamous species. In this study, we summarized the taxonomic treatment of 11 species within the D. varia complex (D. bissetiana, D. chichisimensis, D. erythrovaria sp. nov., D. hikonensis, D. insularis, D. kobayashii, D. protobissetiana, D. sacrosancta, D. saxifraga, D. subhikonensis sp. nov., and D. varia) on the basis of their genome constituents revealed by molecular analyses.
A new species, Cerasus kumanoensis T. Katsuki (Rosaceae), sp. nov., is described from the southern Kii Peninsula, Japan. It is similar to C. jamasakura var. jamasakura and C. leveilleana because the corymbose inflorescences and extended peduncle are identical in these three taxa. However, C. kumanoensis is distinguished by several morphological and phenological characteristics, an earlier flowering period, narrowly ovate and smaller leaf blade (4–8 cm long, 1.8–3.6 cm wide) and glabrous petiole and pedicel.
Geranium yesoense (Geraniaceae) includes several varieties that are mainly discriminated by two morphological features, namely, the degree of leaf incision and the density of spreading hairs on the sepals, but these features have never been objectively quantified. To clarify whether these features can truly discriminate varieties, we analyzed leaf shape and sepal pubescence, and conducted a molecular phylogenetic analysis using nuclear and chloroplast DNA. Our morphological analyses showed some trends in leaf morphology and density of hairs, but failed to identify any groupings that could be clearly distinguished on the basis of these features. Our molecular analysis recognized G. yesoense as a distinct taxon, but did not support the existence of subgroups within the species. We conclude that G. yesoense must be treated as a single taxon with some tendency toward morphological variation depending on locality and habitat.