Palicourea seleri is characterized within its species group by its densely pilosulous stems, leaves, stipules, inflorescence axes, and bracts; petiolate, elliptic to lanceolate leaf blades with acuminate apices; pedunculate, pyramidal inflorescences with the flowers borne in short to lax cymes; deeply lobed, relatively short calyx limbs 0.5-1 mm long; and funnelform white corollas with the tube 6-9 mm long. The bracts are quite narrow, and mostly lack a flattened lamina. The flowers are initially usually closely set, especially in bud, then as flowering proceeds the axes and pedicels elongate and separate them. Many of the flowers are sessile, and the developed axes and pedicels range only up to 2.5 mm long. In some plants the inflorescence axes hardly elongate so the inflorescences are relatively quite short and congested, and these are distinctive but represent the end-points of continuous variation in inflorescence arrangement. Palicourea seleri is similar to Palicourea galeottiana and Palicourea persearum, and these were previously all included within the circumscription of Palicourea galeottiana (Taylor & Lorence, 1992; Taylor, 2012). With their separation, some names that Taylor & Lorence synonymized with Palicourea galeottiana instead match Palicourea seleri.

Palicourea seleri is similar to and apparently closely related to several other species that are also found in Mexico and Central America; see the page for Palicourea galeottiana for a key to these.