First molecular phylogenetic insights into the evolution of Eriocaulon (Eriocaulaceae, Poales)

Eriocaulon is a genus of c. 470 aquatic and wetland species of the monocot plant family Eriocaulaceae. It is widely distributed in Africa, Asia and America, with centres of species richness in the tropics. Most species of Eriocaulon grow in wetlands although some inhabit shallow rivers and streams with an apparent adaptive morphology of elongated submerged stems. In a previous molecular phylogenetic hypothesis, Eriocaulon was recovered as sister of the African endemic genus Mesanthemum. Several regional infrageneric classifications have been proposed for Eriocaulon. This study aims to critically assess the existing infrageneric classifications through phylogenetic reconstruction of infrageneric relationships, based on DNA sequence data of four chloroplast markers and one nuclear marker. There is little congruence between our molecular results and previous morphology-based infrageneric classifications. However, some similarities can be found, including Fyson’s sect. Leucantherae and Zhang’s sect. Apoda. Further phylogenetic studies, particularly focusing on less well sampled regions such as the Neotropics, will help provide a more global overview of the relationships in Eriocaulon and may enable suggesting the first global infrageneric classification

Obtaining new records of critically endangered Potamogeton praelongus (Potamogetonaceae) depending on groundwater springs in northern coastal areas of Hokkaido, Japan

Potamogeton praelongus Wulfen is an aquatic macrophyte that is critically endangered in Japan. Although it is widely distributed throughout the boreal climatic zone, several European countries also recognize it as an endangered species. In Japan, it was once widely distributed throughout Hokkaido but has dis-appeared or reduced in abundance at its known locations. During 2020-2021, we discovered five new locations of this species in Wakkanai-shi and Sarufutsu-mura, Northern Hokkaido. Growing conditions must be suitable for this species in three of the five locations as it is present with several reproductive shoots or is widely distributed in source pond or lake. However, conditions were poor in the other two locations because few shoots were found or plants were observed only in 2020. Environmental condi-tions in the new locations were similar to those reported in Europe and North America. In three of the four locations at Wakkanai-shi, P. praelongus was distributed mainly along the eastern shore facing sand dunes or hills, suggesting that the distribution of this species depends on groundwater springs flowing from sand dunes or hills. Further populations may be discovered in the future by intensively surveying areas near springs since many sand dune lakes and similar environments are present in Hokkaido.(c) 2022 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/)

A New Record of Potamogeton xangustifolius J. Presl (Potamogetonaceae) in Japan

Potamogeton xangustifolius (P. gramineus x P. lucens) was newly recorded in Japan from a pond in Tsugaru-shi, Aomori Prefecture. The hybrid nothospecies was identified based on morphological observations and measurements, molecular analyses using cloned nuclear adhA gene and chloroplast rpl20rps12 intergenic spacer, and pollen viability. The putative hybrid had morphological traits intermediate between P. gramineus and P. lucens, nuclear haplotypes matching those of the two parental lineages, and lower pollen viability than P. lucens (not compared with P. gramineus). The maternal lineage of the hybrid was presumed to be P. gramineus, based on chloroplast sequences. The hybrid characteristically shows well-branched stems in the upper part of shoots, as in P. gramineus, and both clearly petiolate and sessile submerged leaves with distinctive netted venation. Similar plants were collected in the 1980s from a ditch near the pond, suggesting that the hybrid may have been present for more than 30 years in this area

The aquatic macrophyte flora of a small pond revealing high species richness in the Aomori Prefecture, Japan

A small semiartificial pond, revealing high species richness with respect to the aquatic macrophytes, was studied in the Aomori Prefecture, Japan. The pond had been completely formed ca. 10 years previously after excavation into a wet bog. To identify and evaluate its aquatic macrophyte flora during 2017-2018, we listed the species of aquatic vascular plants and charophytes in the pond and compared this list with those from the natural Japanese lakes using a database of aquatic flora in Japan. Two species were identified by molecular analyses because they lacked any reproductive organs, which were necessary for identifying the species level. We found a total of 57 taxa of aquatic macrophytes including 15 Red List species in Japan or Aomori Prefecture. Comparing the flora list with those from the 66 natural Japanese lakes surveyed since 2001, the pond was ranked fourth in the order of diversity (based on species richness) and rarity (based on numbers of Red List species). Therefore, the pond is an important aquatic environment in terms of aquatic macrophyte conservation in Japan. Interestingly, for a pond with such high species diversity, it is relatively small (0.14 km(2)), semiartificial, and relatively recently formed. (C) 2019 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier