Answer: A database search came up with 63 varieties of Mentha, but the only thing that sounded close was Black Mitcham Peppermint, which has dark green foliage and purple stems. It's available through:
Nichols Garden Nursery 1190 No. Pacific Hwy. Albany, OR USA 97321-4580
Another good source for unusual mints is Richters Herbs, http://www.richter.com.
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