Phoneutria, commonly known as Brazilian wandering spiders, armed spiders ("aranhas-armadeiras", as they are known in Portuguese

Brazilian Portuguese

Brazilian Portuguese is a group of Portuguese dialects written and spoken by most of the 190 million inhabitants of Brazil and by a few million Brazilian emigrants, mainly in the United States, United Kingdom, Portugal, Canada, Japan and Paraguay....

), or banana spiders (not to be confused with the relatively harmless species of the genus Nephila

Golden silk orb-weaver

The golden silk orb-weavers are a genus of araneomorph spiders noted for the impressive webs they weave. Nephila consists of numerous individual species found around the world. They are also commonly called golden orb-weavers, giant wood spiders, or banana spiders...

), are a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of aggressive and highly venomous spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s found in tropical South

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 and Central America

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

. These spiders are members of the Ctenidae family of wandering spiders.

The Brazilian wandering spiders appeared in Guinness World Records

Guinness World Records

Guinness World Records, known until 2000 as The Guinness Book of Records , is a reference book published annually, containing a collection of world records, both human achievements and the extremes of the natural world...

2010 as the world's most venom

Venom

Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...

ous spider.
The genus Phoneutria (Greek for "Murderess") contains eight scientifically described

Binomial nomenclature

Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

.