This slender species is characterized by its rather small leaves and stipules, rather small yellow pyramidal inflorescences, rather well developed calyx imbs, and rather small yellow to white corollas with well developed horns or projections on the back or abaxial sides of the corolla lobes, and pyrenes that are smooth abaxially. The calyx limb varies markedly in size and form, but the variation seems to be continuous. The calyx limb ranges from ca. 0.8 mm long and lobed for ca. 1/2 its length with deltate to narrowly triangular lobes; to 1--1.2 mm long and deeply lobed with narrowly triangular lobes (types of Palicourea buchtienii and Palicourea cornifolia; to 2--3 mm long and deeply lobed, with narrowly triangular lobes that are often spreading at the tips (type of Palicourea verrucifera). Plants with unusually large calyx lobes are found sporadically throughout the range of the species (e.g., Cajamarca, Díaz et al. 3886; Ucayali, Graham 4918; La Paz, Fuentes & Huaylla 12918; Santa Cruz, Muñoz et al. 315; Cochabamba, Davidson 5149.) The calyx lobes also vary from usually all about equal in length to unequal, with one lobe twice as long as the shortest lobe. The corollas are glabrous to hirtellous externally, with tubes apparently vary from 7--14 mm long. The abaxially smooth pyrenes are unusual and distinctive, although they are found in a few other species in the same region.

Palicourea buchtienii is sometimes confused with Palicourea subtomentosa, which however has corollas that are externally desnsely pilosulous and have abaxially smooth lobes. Additionally Palicourea subtomentosa has blue to purple corollas, except in northernmost Peru and in Ecuador where this species does have yellow corollas. Palicourea buchtienii is also similar to Palicourea microcarpa, which has similar but larger fruits, short shallowly lobed calyx limbs, corolla lobes without abaxial appendages, and often somewhat spiciform inflorescence axes. Palicourea buchtienii is also similar to Palicourea subcuspidata, which has similar but shorter corollas, pyrenes that are abaxially smooth and subglobose, so the fruits are didymous, and a habitat a low elevations.