This is a small species with sterile leaves shorter than 13 cm long. It belongs to Elaphoglossum sect. Setosa, which is characterized by the presence of subulate scales and conspicuous hydathodes. Although superficially similar to E. piloselloides, with which it is often confused in herbaria, E. horridulum is more closely related to E. costaricense and E. siliquoides (unpubl. data). These three species are characterized by sterile leaves with obtuse apices, abundant glandular hairs, and perine of spores with broad continuous folds, perforations, and spines. Elaphoglossum horridulum is widely distributed in South America, occurring in Colombia, Venezuela, Peru, Bolivia, and Brazil. It is a rheophyte, growing in places that are rarely occupied by other species of the genus (i.e., river beds and river banks that are regularly flooded after heavy rains).