Elaphoglossum pattersoniae is a very rare species of fern that is native to Peru and Bolivia. It is very close to E. guamannianum, but is smaller in size, its blade apex is acute-obtuse, it lacks dark arachnidoid scales on its abaxial costa and has fewer blade scales. It is named after Juliet Patterson, a New York Botanical Garden collaborator.
Its rhizome is compact and horizontal; its scales linear and a lustrous red-brown in colour, about in size. Phyllopodia are present, with fasciculate fronds which are between long and between broad. Its scales are between . Its veins are at a 55-60ð angle, and hydathodes are lacking. Its costal scales are of an orange-tan colour and it lacks intersporangial scales.