This name is a synonym.
Carex caryophyllea var. insularis (Christ) Briq., Prodr. Fl. Corse 1: 204 (1910).
Carex caryophyllea proles insulana Rouy in G.Rouy & J.Foucaud, Fl. France 13: 443 (1912).
Carex insulana (Rouy) Prain, Index Kew., Suppl. 5: 48 (1921).
Carex caryophyllea subsp. insularis (Christ) Arrigoni, Boll. Soc. Sarda Sci. Nat. 23: 220 (1984).