Breutelia is a genus of robust plants found mostly at high elevations in the Neotropics. The genus has some distinctive, easy to recognize species, but most are taxonomically difficult. Two characters of critical taxonomic importance are leaf stance and the degree or type of alar region differentiation. Unfortunately, proper character state evaluation of these features often requires previous familiarity with the genus. There are two basic leaf stances: spreading from the insertion and sheathing at the base. This leaf stance distinction is used in the beginning of many keys to the species of Breutelia (Bartram 1949, Griffin 1994, Churchill & Linares 1995). It works tolerably well, but for some species it is difficult evaluate because the two forms grade into one another and sometimes both can be found within single collections. Likewise, the degree or type of alar region differentiation, which often involves subtle distinctions, can be difficult to evaluate because of variation both within and among collections. Proper evaluation of this last feature requires the examination of many leaves.

Breutelia is closely related to Philonotis, and although the two genera are generally easy to distinguish due to the larger size of Breutelia, technically, they are difficult to separate. Sporophytically, the genera are identical; gametophytically, only the larger size, generally narrower and longer leaf cells, consistently plicate leaf bases and differentiated alar cells of Breutelia separate the two genera. However, Philonotis approximates Breutelia in all these features; even their size distinction is blurred since large plants of Philonotis sphaericarpa (Hedw.) Brid. and small plants of Breutelia jamaicensis (Mitt.) Jaeg. overlap in size.