Crotalinae in the context of "Viperinae"

Haemotoxins, hemotoxins or hematotoxins are toxins that destroy red blood cells, disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. The term haemotoxin is to some degree a misnomer since toxins that damage the blood also damage other tissues. Injury from a haemotoxic agent is often very painful and can cause permanent damage and in severe cases death. Loss of an affected limb is possible even with prompt treatment.

Haemotoxins are frequently employed by venomous animals, including snakes (vipers and pit vipers) and spiders (brown recluse). Animal venoms contain enzymes and other proteins that are haemotoxic or neurotoxic or occasionally both (as in the Mojave rattlesnake, the Japanese mamushi, and similar species). In addition to killing the prey, part of the function of a haemotoxic venom for some animals is to aid digestion. The venom breaks down protein in the region of the bite, making prey easier to digest.

The timber rattlesnake (Crotalus horridus), also known commonly as the canebrake rattlesnake and the banded rattlesnake, is a species of pit viper in the family Viperidae. The species is native to the eastern United States. Like all other pit vipers, it is venomous, with a very toxic bite. Its venom is extremely potent, and both hemorrhagic and neurotoxic venom are present depending on population and location. C. horridus is the only rattlesnake species in most of the populous Northeastern United States and is second only to its relatives to the west, the prairie rattlesnake, as the most northerly distributed venomous snake in North America. There are no subspecies that are recognized as being valid.