Today I was trying to track down which workflows were fired on modification of a specific field. This info is all stored in the WORKFLOW table in the SQL DB, so the following SQL Scrap was enough to locate the offending workflow.
declare @FieldNamePartial as varchar(250)
select @FieldNamePartial = '<FIELDNAME>'
SELECT Workflow.ActiveWorkflowIdName AS WorkFlowOnField, Workflow.TriggerOnUpdateAttributeList AS TriggeredByField, EntityLogicalView.Name as EntityName
FROM Workflow LEFT OUTER JOIN
EntityLogicalView ON Workflow.PrimaryEntity = EntityLogicalView.ObjectTypeCode
WHERE (Workflow.TriggerOnUpdateAttributeList LIKE '%' + @FieldNamePartial + '%')
Just replace the <FIELDNAME> with part of the field you are looking to find.
As with any code you find on the internet - use at your own risk.