Carex × terschellingensis hybr. nov. [= Carex acuta × C. trinervis] and Carex × reichgeltii hybr. nov. [= Carex acuta × C. aquatilis], Cyperaceae, found in the Netherlands

Hitherto, the extremely rare hybrid of Carex acuta and C. trinervis has worldwide only been found in the Netherlands. The hybrid was first found in 1952 on the island of Terschelling (Province of Fryslân), while the latest find, in 2014, is also from Terschelling. Therefore, the authors provide here this hybrid with the name Carex × terschellingensis. Furthermore a type has been selected. Apart from the occurrence on Terschelling, the hybrid is also known from Meijendel (Province of Zuid-Holland), where it was found in 1978. The hybrid between Carex acuta and C. aquatilis is known from the United Kingdom, the Netherlands (this study), Germany, Norway, Sweden, Finland, Estonia, Latvia, and Russia, but was lacking so far a binomial name. The name Carex × reichgeltii is here proposed for this hybrid. The name is in honour of Theodorus Johannes Reichgelt (1903 –1966), a Dutch botanist who paid a lot of attention to the genus Carex in the Netherlands. Furthermore, a type has been selected for this hybrid.