[3][4] It was named after Letizia del Gallo Roccagiovine (1848–1863), granddaughter of the ornithologist Charles Bonaparte.

[6] Graves described the specimens of Letitia's thorntail, but noted that the perceived colors of hummingbirds depend on the lighting and the observer's angle of view.

The crown is brilliant golden-green that blends to dark bronze-green on the back with some coppery-bronze iridescence.

The chin and upper breast are golden-green like the crown with a diffuse pale pectoral band below the latter.

[1] Its "distribution [is] uncertain due to doubts over provenance of specimens" so it is possible that the species still exists undetected elsewhere than Bolivia.