The Aristolochic acid reference article from the English Wikipedia on 24-Jul-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)
Aristolochic acid is a rodentcarcinogen found in Aristolochia species and in Asarum species, both in the Aristolochiaceae family of plants. Aristolochic acid occurs in two forms, aristolochic acid I and aristolochic acid II.