Isoëtes Palmeri with a distribution in the High Andes from the Páramo of Venezuela to the Páramo of Ecuador is described as a new taxon, and dedicated to the then American specialist of the genus, Thomas Chalkley Palmer (1860-1934). The new species belongs to the tropical-Andeanaustral-antarctic section Laeves, described as new here as well. The publication of the new species had to be anticipated to the projected monographic treatment of the South-American representatives of the genus Isoëtes, as A.M. Cleef, Utrecht intends to base a new association, the Isoëtetum Palmeri on this new taxon, observed and collected by him at many instances within the Colombian Páramo between 1971 and 1980 in the context of the preparation of his doctoral thesis now under way.