Anisognathus: Gr. Anisos= unequal and gnathos= lower jaw; alluding to the stubby, almost bullfinch-like bills of these mountain tanagers. lacrymosus: L. lacrima= tear, lacrimosus= tearful, weeping, mournful, piteous.
It is around of 18 cm (7 in) of lenght. The Lacrimose Mountain-Tanager is blue above and orange-yellow below. It has a blue patch on the shoulder. It also has a distinctive yellow area below the eye. The sub-species coerulescens has an additional yellow patch behind the ear.
Tachyphonus lacrimosus = Anisognathus lacrymosus, illustration in du Bus de Gisignies Esquisses ornithologiques, 1846.
The species A. lacrymosus was first described by the Belgian naturalist Bernard du Bus de Gisignies in 1846 under the scientific name Tachyphonus lacrymosus; its type locality is: «Maraynioc, Peru».
It is distributed disjointly along the Andes mountain range and adjacent areas, from northwestern Venezuela (Trujillo), through Colombia, eastern Ecuador, to south central Peru (Cuzco, where it is rarer).
The Lacrimose Mountain-Tanager is uncommon in montane forests of the east and west (Piura and Cajamarca) slopes of the Andes at elevations ranging between 1800-3500 m. It also occurs in Co and Ec.
Recent extensive phylogenetic studies by Burns et al. (2014) show that the present species is the sister of Anisognathus igniventris, and the pair formed by both is the brother of Anisognathus melanogenys.
According to the classifications of the International Ornithological Congress (IOC)  and Clements Checklist / eBird v.2019 , nine subspecies are recognized, with their corresponding geographical distribution:
- Anisognathus lacrymosus pallididorsalis Phelps, Sr & Phelps, Jr, 1952 – Serranía del Perijá (border between Colombia and Venezuela).
- Anisognathus lacrymosus melanops (Berlepsch), 1893 – Andes of western Venezuela (Trujillo, Mérida and Táchira)
- Anisognathus lacrymosus yariguierum Donegan & Huertas, 2010 – north of Colombia (Serranía de los Yariguíes, Santander)
- Anisognathus lacrymosus intensus Meyer de Schauensee, 1951 – eastern slope of the western Andes of southwestern Colombia (Valle and Cauca).
- Anisognathus lacrymosus tamae (Phelps, Sr & Gilliard), 1941 – mountains of north central Colombia and southwestern Venezuela.
- Anisognathus lacrymosus olivaceiceps (Berlepsch), 1912 – northern part of the central and western Andes of Colombia (south to Quindío).
- Anisognathus lacrymosus palpebrosus (Lafresnaye), 1847 – Andes of southwestern Colombia (Nariño) and eastern Ecuador.
- Anisognathus lacrymosus caerulescens (Taczanowski & Berlepsch), 1885 – mountains from southern Ecuador (Loja) to northern Peru (Cajamarca, Amazonas)
- Anisognathus lacrymosus lacrymosus (Du Bus de Gisignies), 1846 – Andes from central Peru (La Libertad to Junín and north of Cuzco).
It forages in the canopy of humid montane forest and second growth, often in the company of mixed species flocks. It is superficially similar to the Buff-breasted Mountain-Tanager and Hooded Mountain-Tanager.