This is a species having showy bracts subtending the branches of the inflorescence. However, there is considerable variability in the size of the bracts, varying even on the same specimen. In Maguire & Wurdack 34815 the largest bracts of the inflorescence are 6-9.5 × 4 mm, whereas the smaller ones of the same collection are only 5 × 2 mm. The isotype and paratype collections of P. bracteata var tenuifolia M.-Arg. have bracts 4-6 × 1.2-2 mm and thus intergrade in size with the smaller ones of the Maguire & Wurdack 34815 collection. Furthermore, there are little or no size distinctions to be found in the bracts of the type collection of P. bracteata var latifolia M.-Arg. (Spruce 3440) and those of P. bracteata var tenuifolia and var intermedia M.-Arg.
Psychotria maguireorum has been confused with P. bracteata A. DC. of the Guianas, and may be distinguished from that species by the glabrous calyx and hypanthium, completely glabrous midrib of the lower side of the leaf, glabrous and longer petioles, differently shaped and broader leaf blades, and longer peduncles and stouter axes of the inflorescence. From the various members of the series which include P. blakei, P. lupulina and variations, P. maguireorum and P. bracteata are immediately separated by having two bracts persisting at the base of the lowest axes of the inflorescence, whereas in the group containing P. lupulina the bracts are present on the axes, but absent at their base. Psychotria maguireorum is also related to P. calochlamys Standl. of the lowlands of the Dept Loreto, Peru, but that species has larger stipules and bracts of the inflorescence.