Great progress in cytotaxonomic research during the last decades indicated an importance of relationships between mor‐ phological features, geographical distribution of plants, and chromosome counts. This study is aimed to ll the gaps in our knowledge on Bolboschoenus chromosome numbers related to morphological di erentiation of plants and their distribution worldwide. We counted gametophytic chromosome numbers in meiotic phase of plants, collected from localities worldwide during the period 1980–2013, and cultivated in an experimental garden in Průhonice. The chromosome numbers of seven species (Bolboschoenus a nis, B. caldwellii, B. grandispicus, B. medianus, B. novae-angliae, B. robustus and B. schmidii) were counted for the rst time. All the studied Bolboschoenus taxa were divided into groups according to chromosome numbers, which were found to correspond to morphotypes formerly described. We have improved the taxonomic classi ca‐ tion of some species. The relationship between chromosome counts and morphotypes appeared to be identical within some continents, and may indicate parallel evolution within the genus.

The encounter with Kazuhiro Soda’s method of observational filming allowed me to reconsider my technical tools and my method of filming the agency of living beings in the Loire estuary. I tested it during a half-day visit to the submerged meadows, where I was guided by one of the few farmers who practise bathing to produce grass regrowth at the end of the summer. The relational approach implemented during the editing process seeks to capture the vibrations that animate these marshes, vibrations that are also at work in the relationship with the recalcitrant digital tools for cutting and editing the shots. The ambition of this documentary to support the work of the collectives encountered and thus to thicken the present is gradually put to the test.