Aristolochia indica is a creeper plant found in Kerala

Kerala

or Keralam is an Indian state located on the Malabar coast of south-west India. It was created on 1 November 1956 by the States Reorganisation Act by combining various Malayalam speaking regions....

 in India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 and also Sri Lanka

Sri Lanka

Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

. This plant is critical to the survival of the Southern Birdwing and Common Birdwing. It reaches a height of several metres on trees and cover the branches with thick foliage. It flowers once a year to produce seeds. It can also be propagated by roots. The plant has a number of historical medicinal uses. This plant contains Aristolochic acid

Aristolochic acid

Aristolochic acids are a family of carcinogenic, mutagenic, and nephrotoxic compounds commonly found in the Aristolochiaceae family of plants, including Aristolochia and Asarum, which are commonly used in Chinese herbal medicine. Aristolochic acid I is the most abundant of the aristolochic acids...

 is a rodent carcinogen

Carcinogen

A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

 found in Aristolochia

Aristolochia

Aristolochia is a large plant genus with over 500 species. Collectively known as birthworts, pipevines or Dutchman's pipes, they are the namesake of the family . They are widespread and occur in the most diverse climates. Some species, like A. utriformis and A...

 and Asarum

Asarum

Asarum is a genus of plants in the birthwort family Aristolochiaceae, commonly known as Wild ginger.- Description :...

, both in the Aristolochiaceae

Aristolochiaceae

The Aristolochiaceae, or the Birthwort family, are a family of flowering plants with 7 genera and about 400 species belonging to the order Piperales...

 family of plants. Aristolochic acid is composed of a ~1:1 mixture of two forms, aristolochic acid I and aristolochic acid II.

In addition to its carcinogenicity, aristolochic acid is also highly nephrotoxic

Nephrotoxicity

Nephrotoxicity is a poisonous effect of some substances, both toxic chemicals and medication, on the kidneys. There are various forms of toxicity. Nephrotoxicity should not be confused with the fact that some medications have a predominantly renal excretion and need their dose adjusted for the...

 and may be a causative agent in Balkan nephropathy

Balkan nephropathy

Danubian endemic familial nephropathy , also called Balkan endemic nephropathy, is a form of interstitial nephritis. It was first identified in the 1920s among several small, discrete communities along the Danube River and its major tributaries, in the modern countries of Croatia, Bosnia and...

. However, despite these well-documented dangers, aristolochic acid still is present sometimes in herbal remedies (such as for weight loss), primarily because of substitution of innocuous herbs with Aristolochia species.