This species is characterized by its flattened stems, elliptic-oblong to ovate, subsessile, clasping leaves, caducous, triangular, interpetiolar stipules that are shortly aristate, terminal cymose inflorescences with flattened peduncles, very short calyx limbs, blue to violet salverform corollas with cylindrical tubes 4.5-6.6 mm long and lobes 3.5-5 mm long, and oblate fruits 5-6 x 6-7 mm. The leaves are quite variable in size. The secondary veins are widely looping in a weakly developed submarginal vein. The leaves are shiny and stiff-textured, and have reduced to shortly developed petioles and rounded to cordulate or cordate bases. The stipules are held erect and pressed together in bud, and appear calyptrate on some specimens. The inflorescences variously have a well developed peduncle or ar subtended by developed leaves; those with leaves have been considered sessile with three fasciculate peduncles by some authors, and "sessile and tripartite" by Standley. The peduncles are not articulated. The flowers are subsessile in short dichasial cymes. The specimens often dry yellowed.
Faramea sessilifolia is variable in leaf size, width, and shape of the base across its range, and this variation is seen in part in the number of names that are here synonymized. Leaf form has been used to distinguish this species. Faramea sessilifolia is similar to and probably related to Faramea tamberlikiana, which differs in its at least shortly petiolate leaves that are rounded to obtuse or acute at the base. Faramea sessilifolia is found in seasonal vegetation, gallery forest, and seasonally inundated areas, while Faramea tamberlikiana is found in wet forest, in both upland and seasonally inundated vegetation. The development of the petiole and leaf base shape are variable in each of these species, and some specimens of each are intermediate in form and classified partly based on habitat and the region where they were collected. These two species overlap in range in the western Amazon basin. These species do appear to be generally distinct; whether these intermediates are hybrids or these are better considered to be subspecies of the same species will require field study.
Faramea sessilifolia is similar to Faramea tamberlikiana, as discussed above. Faramea sessilifolia is also similar to Psychotria amplectens, which has bilobed stipules, white flowers, and well developed inflorescence bracts. Faramea sessilifolia is also frequently confused with Faramea sessiliflora, which differs notably in its petiolate leaves and flowers arranged in a few heads that are enclosed by well developed brats but has a similar species name. Faramea sessilfolia is also similar to Faramea obtusifolia of Goiás in east-central Brazil, with a few fasciculate larger flowers; neither of these species were included by Delprete (2010).