What does black tissue in a venous stasis ulcer mean?

Vascular surgeon: It is dead, necrotic tissue. It needs to be debrided (cut) or put a cream called santyl on it. Discuss with your primary care doctor. Get a referral to go to a vascular surgeon.

Wounds: I would more often see dark brown pigmentation due to stagnant blood material under skin. Gradually may open up as a wound.

Black in ulcer: 'black' tissue can be several things in an ulcer. It can represent decayed tissue, infected tissue, affects of silver based dressings, etc. Please go to a wound center to be seen.