A condition in which injured or diseased body tissue dies due to a lack of
blood flow, then becomes infected by
bacteria (especially from the genus
Clostridium) and begins to decay.
Gangrenous tissue often turns
black because bacteria make
iron sulfide from the iron in decaying
hemoglobin.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.