Acta Phytotaxonomica et Geobotanica

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Volume 75 (2024) Issue 2 Pages 51-69

Biosystematic Studies on Commelinaceae (Commelinales) II. Phylogeny and Floral Evolution in Murdannia

Chung-Kun Lee, Shizuka Fuse, Manop Poopath, Rachun Pooma, Shuichiro Tagane, Yong-Ping Yang, Hiroshi Tobe, Minoru N. Tamura

Murdannia (Commelinaceae), consisting of some 60 species, is unusual in the family in having both actinomorphic and zygomorphic flowers usually with the median petal on adaxial side, and having either two or three antisepalous stamens. To understand floral evolution in the genus in light of a phylogenetic context, we conducted phylogenetic analyses of 18 species and one cultivar mainly from Asia using plastid DNA sequences, then examined their respective floral morphology. The results showed a monophyly of all 16 Asian species of Murdannia and one cultivar, and of the ten species with zygomorphic flowers. Comparisons with flowers of related genera suggest that great morphological changes occurred early in the evolution of Murdannia, including rotation of a symmetrical plane by 60 degrees so that the median petal of the flowers is positioned at the top on the adaxial side. Within the genus, a change in floral symmetry from actinomorphy to zygomorphy occurred one time and was accompanied by androecial zygomorphy resulting from replacement of one of three antisepalous stamens by a staminode. Additionally, the two latero-abaxial petals usually spread laterally around 160–180 degrees. The infrageneric classification of the Asian species is also briefly discussed.

Editor's pick

A paper awarded the Best Paper Prize 2025

Volume 75 (2024) Issue 2 Pages 97-111

Biosystematic Studies on the Genus Polygonatum (Asparagaceae) VI. Polygonatum ×hizenense and P. ×sefuriense, Two New Hybrids from Japan

Riko Masuda, Hiroshi Noda, Kazunori Shintaku, Nam Sook Lee, Shizuka Fuse, Minoru N. Tamura

Based on morphology as well as on karyotype and MIG-seq analyses, two new hybrids, Polygonatum ×hizenense and P. ×sefuriense, from Mt. Sefuri, Pref. Saga, Japan, are described. Polygonatum ×hizenense has 26–29% pollen stainability and 2n = 20, is morphologically intermediate between P. falcatum (with 78–98% pollen stainability and 2n = 18) and P. macranthum (with 95–100% pollen stainability and 2n = 22), which occur parapatrically on Mt. Sefuri. A Neighbor Net network based on MIG-seq data showed P. ×hizenense to be positioned between the P. falcatum cluster and the P. inflatum-P. macranthum cluster, also indicating it to be of hybrid origin between P. falcatum and P. macranthum. Likewise, P. ×sefuriense has 29–37% pollen stainability and 2n = 19, morphology intermediate between P. amabile (with 74–92% pollen stainability and 2n = 20) and P. falcatum, which also occur parapatrically on Mt. Sefuri. The MIG-seq analysis showed P. ×sefuriense to be positioned between the P. falcatum cluster and the P. amabile-P. lasianthum var. lasianthum cluster in the obtained network, indicating it to be of hybrid between P. amabile and P. falcatum. In addition, our analysis based on MIG-seq suggested that P. lasianthum var. coreanum should be separated from var. lasianthum as a distinct species, P. taquetii.

Editor's pick

A paper awarded the Best Paper Prize 2025

Volume 74 (2023) Issue 1 Pages 1-15

Hidden Diversity of Ferns: Haplopteris mediosora Have Survived as Independent Gametophytes in Japan

Katsuhiro Yoneoka, Kiyotaka Hori, Toshifumi Kataoka, Tao Fujiwara, Atsushi Ebihara, Noriaki Murakami

Haplopteris mediosora (Hayata) X. C. Zhang (Pteridaceae), a fern with linear simple fronds is widely distributed at high elevations from the Himalayas through China, the Philippines and Taiwan to Japan. In Japan, sporophytes of H. mediosora were recorded only from Azusa-shiraiwa, a mountain of Okuchichibu region, and have not been seen for over 50 years. The hypothesis that such rare species still persist as gametophytes was proven during this study when gametophytes were found on several mountains in the Oku-chichibu region. Phylogenetic analysis of rbcL sequences collected in this study demonstrated that the gametophytes, identified as H. mediosora, and sporophytes of H. mediosora formed a clade and were distinct from related species of Haplopteris. The gametophytes were also growing independently because of the absence of sporophytes. A comparison of the haplotypes of the matK and trnL-F regions showed that the gametophytes had two chloroplast DNA haplotypes. The polymorphisms may have been derived from ancestral sporophytes that were present in Japan during the glacial period. Despite the rarity of sporophytes in the area, the independent gametophytes occur in four distant localities in the Oku-chichibu mountains.

Editor's pick

A paper awarded the Best Paper Prize 2024

Volume 74 (2023) Issue 2 Pages 71-103

Biosystematic Studies of Carex (Cyperaceae) III. Phylogenetic Analyses of the Carex filipes complex (sect. Paniceae) in East Asia, with Reference to Morphology, Karyology and Taxonomy

Kotaro T. Takahashi, Jiro Oda, Shizuka Fuse, Okihito Yano, Yi-Fei Lu, Xiao-Feng Jin, Minoru N. Tamura

Calex filipes (Cyperaceae) and its closely related species, which we tentatively refer to as the C. filipes complex, are greatly diverse morphologically. The closely allied species have often been included within C. filipes where they have been treated by as many as seven infraspecific taxa at the rank of variety. To better determin the taxonomic distinctness of the individual species and infraspecific taxa, we undertook molecular phylogenetic analyses of individuals of the C. filipes complex using the plastid DNA regions atpB–rbcL, rpl16–rpl16–rps3, rps16, matK, and trnL–trnL–trnF and nuclear DNA regions ITS and ETS. We compared the morphology of as many individuals as possible and determined the somatic chromosome number of some individuals to supplement missing information. It was concluded that the C. filipes complex comprises ten species, two varieties and one hybrid, i.e. C. arisanensis, C. curtispica, C. egena, C. filipes var. filipes, C. filipes var. tremula, C. kujuzana, C. ×kurogii, C. kuzakaiensis, C. rouyana var. arakiana, C. rouyana var. rouyana, C. sohayakiensis, C. sparsinux and C. vaniotii. A diagnostic key to separate them, based on morphology, and chromosome numbers are presented. Two new species, C. curtispica and C. sohayakiensis and one new hybrid, C. ×kurogii, are described. The origin of the hybrid isalso discussed.

Editor's pick

A paper awarded the Best Paper Prize 2024

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2025 Volume 76 Issue 1

First Record of the Mycoheterotrophic Orchid Aphyllorchis montana var. rotundatipetala (Orchidaceae) from Amami-Oshima Island, Ryukyu Islands, Japan Kenji Suetsugu
Scapania bhutanensis (Scapaniaceae) New to India Tian-Xiong Zheng
Surviving at the Southern Edge: The Rear-Edge Population of Viola brevistipulata var. acuminata Persisting in Disturbance-Mediated Refugium Shota Sakaguchi, Shigeru Fukumoto, Taro Fujimura, Shun K. Hirota, Kazuki Yamamoto, Masae I. Ishihara
Eulophia siamensis (Epidendroideae: Orchidaceae) from Sikkim; a New Record for the Flora of India Pramod Rai, Santosh Kumar Rai , Prakash Limboo, Sudhizong Lucksom

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