It is sold on the internet by over seas companies as an essential oil, otherwise I didn't see it for sell as an herb for tea, powder, etc.

There are thousands of herbs that have came into popularity and no longer sold commercially in the USA, simply because there is NO MARKET until some author makes it popular again and THEN everybody an their brother will sale it. Look at all the juices, berries, herbs doctors have promoted from other countries that went nuts in the states for about 2 years, about the time the population discovers the herb/berry/juice was not worth the asking price and then it fades away into the past.

You can also find alot of herbs sold not by herb companies, but by flower/plant companies. Seems they can sell all kinds of toxic herbs at flower/herb companies to raise for ornimental use. I have one amish guy that seems to use all the old toxic herbs and almost nothing he ask for is on the open marlet anymoe, simple because idiots OD on such narcotic type herbs.....yet most of what he ask for can be purchased to raise as flowers or plants around the garden for "show" and not human use. So where there is a will, there is a way.....even i after 10 years of searching for desert parsley, found a lonely woman living on top of a mountain that for a few bucks, rode her mule for days around and around the mountain until she dug me up so much desert parsley that I have zero doubts that I have the largest collection of the rare desert parsley roots on earth.

Your yam lives at the same altitude as desert parsely, up where normal humans don't live because it is too cold and all rock and trees. Such plants often can never be brought down and raised in gardens, I tried with the desert parsly and it lived about 1 year.

MH