In Colombia and neighboring areas there are three species of Breutelia which produce smooth or rugulose (not longitudinally plicate) capsules. These are: B. subarcuata (C. Muell.) Schimp. in Besch., B. squarrosa Jaeg. and B. rhythidioides Herz. Although all are similar in gross morphology, they can be distinguished by the areolation of the alar region of the leaves. In B. squarrosa the alar region is scarcely distinct with no more than 1-3 inflated, hyaline cells in the basal corners and with a few enlarged supraalar cells. In both B. subarcuata and B. rhythidioides the alar region is clearly distinct with 2 or more rows of enlarged pells and with the outer 1 -2 rows of inflated, hyaline cells. The intramarginal alar cells in B. subarcuata are non-porose, or essentially so, while in B. rhythidioides the intramarginal alar cells are quite porose. A review of type and secondary collections shows that the three members of this complex are wide-ranging in the neotropics but apparently with the highest frequency of populations in the northern Andes. B. rhytidioides Crum is rejected as a horn, illeg.