This species has not been collected very frequently. It can be recognized by its generally medium-sized, elliptic or quite oblong leaves that are rugulose and moderately to densely hirtellous to woolly below, its medium-sized inflorescences, its rather well developed calyx limbs, and its medium-sized flowers with the corolla tube ca. 9 mm.

Cinchona parabolica is rather similar to C. mutisii and C. rugosa, which are also found in the mountains of southern Ecuador; those last two species can be separated by their smaller leaves, smaller inflorescences, and generally larger flowers with usually longer calyx limbs as well as corolla tubes. Cinchona parabolica is similar to C. scrobiculata, but C. scrobiculata can be separated by its generally plane leaves and calyx limb that is densely puberulous to strigillose inside, vs. rugulose leaves and inyernally glabrous to sparsely puberulous calyx limbs in C. parabolica. Cinchona parabolica is also similar to C. fruticosa, but C. fruticosa can be separated by its leaves that are often smaller, generally glabrous or only sparsely pubescent below, and have only the secondary veins very thinly impressed or sometimes also some of the tertiary venation irregularly so.

Plants from the Cordillera del Cóndor with often relatively small leaves are provisionally included here. These are mostly reported as collected on crystalline rock substrates, at 1200-2000 m. The measurements of these plants match those of Cinchona parabolica as circumscribed by Andersson, although in general aspect the plants from this region can be separated by a vague morphological difference.