Bolboschoenus planiculmis (Cyperaceae), a third species of Bolboschoenus for the Netherlands

In 2017 Bolboschoenus planiculmis (F. Schmidt) T.V. Egorova (basionym: Scirpus planiculmis F. Schmidt) was discovered in the Grensmaas area in the Province of Limburg in the southeastern part of the Netherlands. The identification of this species, with its bifid styles and biconcave achenes, was straightforward. Later, the first author found a second specimen of this species in the herbarium of the Dutch Plant Protection Organisation, now part of the Netherlands Food and Consumer Product Safety Authority, which was collected in 2002 as a possibly harmful plant in a tree nursery at Sambeek in the Province of Noord-Brabant near the River Meuse. We provide a brief description of this species and a key to the Bolboschoenus species in the Netherlands.