This is the most widespread and commonly encountered species of Hamelia, and probably of all Neotropical Rubiaceae. It is characterized by its shrubby habit with persistent, narrowly triangular stipules and opposite or verticillate leaves; its terminal cymose inflorescences; its showy, orange to red or occasionally yellow, tubular corollas; and its often scorpioid fruiting axes. The plants are commonly found in sunny secondary vegetation, and often flower and fruit simultaneously and apparently more than once per year. Hamelia patens is often confused with Palicourea, but Palicourea differs in its bilobed stipules, corollas often asymmetrically swollen at the base, bilobed stigmas, and fruits with two pyrenes (vs. triangular stipules, corollas symmetrical at the base, simple or 5-lobed stigmas, and fruits with many small seeds in Hamelia).

Elias (1976) separated two varieties of this species, based on pubescence. Hamelia patens var. patens is more widespread and commonly encountered; Hamelia patens var. glabra Oerst. is found widely and discontinuously within the range of var. patens. Some authors have followed Elias in recognizing these, while others have not. No ecological or geographic characterization of either of these varieties was given by Elias. He noted (p. 112) that the density and form of the pubescence varies widely across its range in var. patens, and that "a complete gradation from the densely to sparsely villous condition is found in the Central American specimens".