This species is characterized by its rather robust, glabrous habit; its well developed, generally obtuse stipules; its rather stiff-textured, elliptic to obovate leaves with an obtuse to rounded apex and mostly moderately developed petioles; its sessile to shortly pedunculate, rounded-corymbiform inflorescences with pedicellate flowers; its rather well developed truncate calyx limb 1.8-3 mm long; its well developed yellow corolla; and its ellipsoid to subglobose, moderately large, apparently yellow fruits. The plants included here in Psychotria anjanharibensis vary rather notably in particular in leaf size, not only across the range of the species but within a particular area (e.g., Marojey, Miller & Lowry 3842, 4041, 4110. This species is here circumscribed based on the combination of stipule, inflorescence, calyx, and corolla characters.
Psychotria anjanharibensis has been confused with Psychotria menalohensis, which (as circumscribed here) differs in its generally smaller oblanceolate leaves, its fastigiate inflorescences with ascending axes, its subsessile to sessile flowers. Psychotria anjanharibensis is also similar to Psychotria onivensis, which differs in its elliptic leaves with a sharply acuminate apex and pyramidal inflorescences; Bremekamp originally separated these also by petiole and peduncle length, but both species seem to vary more than he noted in these features. Psychotria anjanharibensis is also similar to Psychotria bridsoniae, which has short calyx limbs, ca. 1 mm long, and usually longer petioles.