A group of temperate grassland plant species, referred to as the ‘Mansen elements,’ is found in Japan and extensively distributed in the grasslands of continental East Asia. It has been considered that these species are remnants of once-expanded grasslands in Japan during a colder geological era. However, the detailed phylogeographic history, including migration age and distributional changes within Japan for these species, remains unresolved. To elucidate the phylogeographic history of the Mansen elements, we investigated the genetic structure and phylogeny of the populations of Pulsatilla cernua, one of the Mansen elements, using single-nucleotide polymorphisms (SNPs) obtained from multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq). The phylogenetic analysis indicates a continental origin and migration route via the Korean Peninsula for P. cernua. The DIYABC and the genetic structure analyses suggest that the divergence between the continental and Japanese populations occurred in the late stage of the Last Glacial Period (LGP). Although the estimated divergence time is not fully constrained, it is suggested that an initial expansion in Japan occurred before the Last Glacial Maximum (LGM). This once-expanded distribution area was subsequently fragmented during the coldest climate, followed by a secondary expansion after the LGP. This represents the first documented instance among the Mansen element species in which secondary range expansion brought fragmented populations into secondary contact.

View full abstract

A new species, Firmiana laotica (Malvaceae), and five new records, Justicia oreophila (Acanthaceae), Aganosma wallichii (Apocynaceae), Colebrookea oppositifolia (Lamiaceae), Myristica yunnanensis (Myristicaceae), and Brachytome hainanensis (Rubiaceae) are reported for the flora of Laos. Voucher specimens, photographs, and ecological information in Laos are provided for each species.

View full abstract

Insufficient diagnostics in the protologue of Frullania warnckeana var. dentosa S. Hatt. may has hampered the understanding of the morphology and taxonomy of this taxon endemic to Vietnam and led to its omission in several liverwort checklists for the country. In this report, a supplementary type-based description and illustration of F. warnckeana var. dentosa is provided for the first time. Since the holotype was not found in EGR, a lectotype for var. detonsa is also designated.

View full abstract

Potamogeton ×apertus Miki (Potamogetonaceae), a hybrid between P. panormitanus (currently treated as a synonym of P. pusillus) and P. oxyphyllus, was described based on specimens collected in Sagami, Tosa, and Iyo provinces, Japan. We have found seven relevant specimens or syntypes in OSA, and designate a specimen collected in Ohtsumura, Tosa Prov. (T. Yoshinaga s.n., 27 Dec. 1933, OSA [OSA309198]) as the lectotype. We exclude two syntypes collected in Sagami Prov. (OSA217323 & 217324) for circumscription of P. ×apertus; They appear be hybrids between different parental species.

View full abstract

Asplenium simaoense K. W. Xu, Li Bing Zhang, and W. B. Liao was found in Shan State, Myanmar. This discovery contributes to a better understanding of pteridophyte diversity in Myanmar and provides insights into species distributions in neighboring China, Laos, and Thailand, emphasizing the need for further taxonomic and conservation efforts.

View full abstract

Eustachys petraea (Sw.) Desv. (Poaceae) is newly recorded as invasive species on Iriomote Island, Okinawa, Japan. We here propose the Japanese name ‘Suisho-gaya’ for this species.

View full abstract