A new endemic plant association, Erico terminalis-Schoenetum nigricantis (All.Molinio-Holoschoenion vulgaris), is described from the thermomediterranean areas of the low- or medium-elevation mountains of the southern parts of Valencia province, which is dominated by Schoenus nigricans, Erica terminalis and E. erigena. This is a dense but poorly characterised black-sedge community, occurring at the base of ?balmas? and dripping limestone cliffs, where deposits of tufa or clay are formed which remain sodden during part of the year due to water emergence. Data on the floristic composition, ecology, distribution and sintaxonomic relationships of this habitat are also reported with regard to other similar communities. Furthermore, the nomenclatural correction Thymo piperellae-Helianthemetum rotundifolii Rivas Goday 1958 corr. Solanas & M.B. Crespo hoc. loc. [Thymo piperellaeHelianthemetum mollis Rivas Goday 1958, nom. incorr.] is stated, since the taxon used to name that Saetabensian scrub is indeed Helianthemun rotundifolium, neither H. molle nor H. marifolium as sometimes it was suggested.