Acta Phytotaxonomica et Geobotanica

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Volume 71 (2020) Issue 2 Pages 103-128

A Large-scale Phylogenetic Analysis of Dioscorea (Dioscoreaceae), with Reference to Character Evolution and Subgeneric Recognition

Hiroshi Noda, Jun Yamashita, Shizuka Fuse, Rachun Pooma, Manop Poopath, Hiroshi Tobe, Minoru N. Tamura

Dioscorea (Dioscoreaceae) is a diverse genus of more than 600 species. To understand relationships and character evolution within the genus, 273 samples from 183 species (including 28 newly sequenced species) based on four cpDNA regions were analyzed phylogenetically. The phylogenetic tree obtained comprised eleven well-supported major clades, most of which further consisted of more than two subclades. Comparisons with previously proposed infrageneric taxa (23 to 58 sections and associated ‘genera’) showed that some sections/‘genera’ are monophyletic and others polyphyletic. As in previous studies, ‘D. sect. Stenophora’ was sister to the rest of the genus. The present analyses of character state distribution on the tree confirmed that ‘D. sect. Stenophora’ is characterized by having rhizomes, monosulcate pollen and a diploid chromosome number based on x = 10 (plesiomorphies), whereas the rest of the genus has tubers and bisulcate pollen (apomorphies), but is diverse in regard to chromosome number, stem twining direction, fruit types and seed wing morphology. Based on molecular and morphological evidence, two subgenera, Dioscorea (= ‘D. sect. Stenophora’) and Helmia, are proposed. For subgenus Helmia, a revision of the infrageneric classification, especially for the species in the Old World, is needed.

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A paper awarded the Best Paper Prize 2021

Volume 71 (2020) Issue 2 Pages 79-101

A Taxonomic Study of Machilus (Lauraceae) in Cambodia based on DNA Barcodes and Morphological Observations

Keiko Mase, Shuichiro Tagane, Phourin Chhang, Tetsukazu Yahara

Based on new collections of Machilus from three locations in Cambodia, six species including four new species are recognized: Machilus angustifolia sp. nov., M. bokorensis Yahara & Tagane, M. brevipaniculata Yahara & Tagane, M. cambodiana sp. nov., M. elephanti sp. nov., and M. seimensis sp. nov. Those species are characterized by DNA sequences of rbcL, matK and ITS and vegetative traits of leaves, young twigs and terminal buds. Among four species collected from the same locality, M. angustifolia and M. brevipaniculata have naked terminal buds, but are distinguished by leaf shape and are not close in the ITS tree; M. bokorensis and M. elephanti have scaly terminal buds but are distinguished by the size and morphology of their terminal buds and are not clustered together in the ITS tree. Two additional species differ in their terminal buds, naked in M. cambodiana and scaly in M. seimensis, and are not clustered together in the ITS tree. Four new species are described by comparison with related species and their conservation status is qualified. A new name M. kerrii comb. nov., based on Phoebe kerrii Gamble, is made.

Editor’s picks

A paper awarded the Best Paper Prize 2021

Volume 70 (2019) Issue 3 Pages 149-158

Rediscovery of Liparis hostifolia (Orchidaceae) on Minami-iwo-to Island in the Bonin (Ogasawara) Archipelago, Japan, and its Identification Using Molecular Sequences from a Herbarium Specimen Collected more than 100 Years Ago

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.

Editor’s picks

A paper awarded the Best Paper Prize 2020

Volume 70 (2019) Issue 1 Pages 1-17

Biosystematic Studies on the Family Piperaceae (Piperales) I. Plastid DNA Phylogeny and Chromosome Number of Peperomia subgenus Micropiper

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.

Editor’s picks

A paper awarded the Best Paper Prize 2020

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2021 Volume 72 Issue 1

Litsea martabanica (Kurz) Hook. f. (Lauraceae): A New Addition to the Flora of Vietnam Luu-Dam Ngoc Anh, Do Van Hai, Bui Van Huong, Nguyen Duy Hung, Luu-Dam Cu, Lydia Kukhareva, Eugene Popoff, Vladimir V. Titok
A New Species of Actinodaphne (Lauraceae), A. lambirensis from Sarawak, Malaysia, and an Analysis of its Phylogenetic Position using MIG-seq and ITS Sequences Norikazu Okabe, Tetsukazu Yahara, Shuichiro Tagane, Chika Mitsuyuki, Ayumi Matsuo, Takanori Sasaki, Etsuko Moritsuka, Kengo Fuse, Usun Shimizu-Kaya, Julia Anak Sang, Runi Sylvester Pungga, Yoshihisa Suyama
New Distributional Record of Lecanorchis nigricans Honda (Orchidaceae) and a New Addition for the Orchid Flora of Indonesia Kenji Suetsugu, Destario Metusala, Yuda Rehata Yudistira
Index to new names and combinations appearing in Acta Phytotaxonomica et Geobotanica 72 (1)

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