Uncaria tomentosa is a woody vine found in the tropical jungles of South and Central America.

Uncaria tomentosa is a liana deriving its name from hook-like thorns that resemble the claws of a cat. U. tomentosa can grow to a length of up to 30m, climbing by means of these thorns.

It favours mountain slopes in the organic soils of the primary (old growth) rainforest, between 250 and 900 meters above sea level. It can also be found in disturbed forest but rarely in secondary forest. Over harvesting and destruction of old growth rainforest are a serious threat to Uncaria tomentosa.