{ { Speciesbox
| image = Bothrops asper (Sierra Llorona, Panama).jpg
| status = LC
| status_system = IUCN3.1
| status_ref =
| range_map = Bothrops asper Area.PNG
| range_map_caption = Geographical range of Bothrops asper. | genus = Bothrops | species = asper | authority = (Garman, 1884) | synonyms = { { Collapsible list|bullets=on | B[othrops]. atrox var. dirus Jan, 1863 | Trigonocephalus xanthogrammus Cope, 1868 | Trigonocephalus asper Garman, 1884| B[othrops]. atrox septentrionalis F. Müller, 1885 | B[othrops]. quadriscutatus Posada Arango, 1889 | Lachesis xanthogrammus – Boulenger, 1896 | Bothrops xanthogramma – Amaral, 1930 | Bothrops atrox asper – H.M. Smith & Taylor, 1945 | Bothrops asper – Stuart, 1963 | Bothrops xantogrammus – Hoge, 1966 | Trigonocephalus xantogrammus – Hoge, 1966 | Lachesis xantogrammus – Hoge, 1966 | Bothrops xantogramma – Hoge, 1966 | Bothrops asper – J. Peters & Orejas-Miranda, 1970 | Bothrops xanthogrammus – J. Peters & Orejas-Miranda, 1970 | Bothrops andianus asper – Mertens, 1987 | Bothrops lanceolatus asper – Sandner-Montilla, 1990 | Bothrops atrox xanthogrammus – Schätti & Kramer, 1993 | Bothrops asper – Greene, 1997 }} }}Terciopelo (Bothrops asper) is a highly venomous species of pit viper found at low to moderate elevations in northeast Mexico and Central America, and into South America where it is known from elevations up to 2600 meters in the Colombian and Ecuadorian Andes, as well as into Venezuela. With a mass of up to and a maximal length of , the terciopelo is among the largest pit vipers. It is light to dark brown in color, often with yellow zig-zag-shaped lines on each side of the body. Dubbed "the ultimate pit-viper" for its large size, fangs and venom yield, it has a fearsome reputation, responsible for the most snakebites within its range because of its defensive temperament and proximity to human residence. However, like other venomous snakes, it avoids confrontation with humans whenever possible. No subspecies are currently recognized.
Etymology
The generic name, Bothrops, comes from the Greek words and , which mean 'pit' and 'face' (or 'eye'), respectively. This is a reference to these snakes' highly sensitive heat-detecting pit organs. The specific epithet, , which is a Latin word meaning 'rough' or 'harsh', may allude to the species' keeled dorsal scales.
Common names
Some of the common names applied to this snake are terciopelo ("velvet" in Spanish), fer-de-lance, mapepire balsain (Trinidad), carpet labaria (Guyana), barba amarilla (Guatemala, Honduras, Nicaragua; "yellow beard"), equis (Ecuador and Panama; "x"), talla equis , mapaná (Colombia), cuaima (Venezuela), nauyaca (México; from Nahuatl nahui, four, and yacatl, nose; "four noses"), and yellow-jaw tommygoff (Belize)."
The name fer-de-lance is French (or possibly Créole), translating to "iron of the lance", "iron spear point" or simply "spearhead" or "lancehead". In English the name lancehead is applied to the genus Bothrops as a whole, and in combination with the majority of the species within the genus (e.g.: Alcatrazes lancehead (Bothrops alcatraz), Patagonian lancehead, (Bothrops ammodytoides), Andean lancehead (Bothrops andianus) etc.). The name fer-de-lance has been used inconsistently and very informally with several species in the genus Bothrops having been called fer-de-lance at one time or another, most commonly Bothrops asper, Bothrops atrox, Bothrops caribbaeus, and Bothrops lanceolatus. Several herpetologists have preferred and argued to restrict the name fer-de-lance to the Martinique lancehead (Bothrops lanceolatus) from the Caribbean Island of Martinique, but popular usage has rarely recognized any distinction. In their seminal opus on the venomous reptiles of the Western hemisphere, Campbell & Lamar stated: "The name fer-de lance, widely used in North America with reference to B. asper and B. atrox, has no legitimate origin of use in regions inhabited by this snake." In an effort to establish standardized names for the amphibians and reptiles of North America, the Society for the Study of Amphibians and Reptiles (SSAR), a not-for-profit organization and one of the largest international herpetological societies, applied the following nomenclature: Bothrops Wagler, 1824: Lanceheads (English) Bothrops asper (Garman, 1884[1883]): Terciopelo (English) In recent decades, herpetologists have preferred the name 'terciopelo' for Bothrops asper, although the term fer-de-lance is still common in popular usage.