Abstract
Viviparous Festuca especially from the North Atlantic area have been examined. Based on especially the chromosome numbers they are divided into three subspecies and a number of hybrids: 1) F. vivipara (L.) Sm. ssp. vivipara, 2) F. vivipara ssp. hirsuta (Schol.) Frederiksen stat. nov., 3) F. vivipara ssp. glabra Frederiksen ssp. nov. Hybrids between F. vivipara on the one hand and F. rubra L. or F. ovina L. on the other were found to be common.