The sole constituent of the genus Chlorornis is a beautifully distinctive and well-named bird. Virtually the entire bird is clad in bright green, relieved only by the chestnut face mask and ventral region, while both the chunky bill and the tarsi and toes are deep red. This bulky bodied, robust looking, sluggish tanager is found in the Andes from Colombia south to Bolivia, and throughout this wide range it is found in wet mossy forest and edges between 1500-3350 m. Grass-green Tanager often joins mixed species flocks, but also travels in pairs or small groups of its own species; the birds take both animal and vegetable matter. The generic name derives from the Greek words khloros, which means green, and ornis, which means bird, referring to the color of its body; the species name riefferii honors Gabriel Rieffer, a collector in the American tropics (Jobling 2010). In Spanish the common name for this species is Tangara Lorito, which translates as the "little parrot tanager" (Hilty 2011, de Juana et al. 2012).