Considered a synonym of Tillandsia demisa L.B. Sm. without comment —SeeLuther & Sieff 1994p. 29
Tillandsia fosteri is kept separated from T. demisa for now. T. fosteri holotype has spreading branches, but the isotype at K has a more cylindric inflorescence with erect branches, still there are some differences. T.demissa is in all flower parts larger and the primary bracts are exceeding the spikes except at the apex. But it seems that there are intermediate forms as in the plant Rauh describes in BSI Journal 37:168-169 (with shorter floral bracts and primary bracts). Could T. fosteri be a natural hybrid of T. demisa? —SeeGouda et al. 2023-