40 pounds of (sorta) edible man-root: Ipomoea leptophylla/pandurata

It all started when I was catching up on Ludi's projects thread and I saw this post from awhile back. She mentioned edible prairie plants and linked to this PDF: Renewing the Native Food Traditions of Bison Nation. Skimming that excellent list, the following caught my imagination:

Bush morning glory, Man-root, Man-of-the-earth root, Wild potato vine, Wild jalap, Kahts-tuwiriki, Mecha-meck (Ipomoea leptophylla and/or I. pandurata).

A huge sweet potato-like root looms below long, trailing, low-growing vines with heart-shaped leaves and funnel-form flowers. Favoring the dry open range of sandy prairies as well as the banks of wallows
and roadsides east of the Rockies, one or the other of these two species can be found from southern Canada to Texas. Both of these morning glory species produce perennial roots that are sometimes shaped like a human body. When dug up, they stand thigh-high, and weigh forty pounds or more.

The Cheyenne, Arapaho, and Kiowa once used it as a survival food in drought years, but found it tough-skinned and exceedingly bitter if not carefully prepared and boiled. When roasted or baked, man-roots have the flavor of slightly bitter sweet potatoes. Neither delicacies nor staples, the starchy roots were also used medicinally to treat kidney, stomach, and urinary disorders and the seeds may have been consumed to induce visions.

Now, I am laboring under no illusion that this "man-root" is a good food crop. I'd assume it's slow-growing and barely edible, from that description. But I very much like the idea of growing high-volume no-attention survival foods in disused corners of my acreage as a hedge against future food insecurity, and this huge sorta-edible root is, in any case, a delightful oddity. A bunch of questions immediately sprang into my mind, so I decided to do some Googling and report my findings here.

First, my questions:

1) If the root is "perennial" I assume that means that very large roots are the result of many years of growth, a la ginseng but on a much larger scale?

2) Just how unattractive is the root as a food? Does it vary in bitterness depending on individual plant genetics or growing conditions?

3) How can the plant be propagated? By seeds, cuttings, roots, or And where can I get some?

And now for the fruits of my research!

Prairie Moon Seeds offers Ipomoea leptophylla seeds for sale. Their detailed range map shows it growing two counties west of me, so it's not completely hopeless for me to grow it if I can find the right conditions on our land.

Eat The Weeds says (of pandurata):

"Can be eaten if cubed and boiled in at least two changes of water. Never eat it raw. Younger and smaller is better. Young roots can also be roasted but they will be on the bitter side. Boiling twice is the preferred method, then roast the boiled cubes if you like. Usually straight down deep from where the vine goes into the ground you will find the root. Yard-long roots weighing 25 pounds are possible. But, they get more acrid the older they get so if you can find an big old one you might want to let it be and look for a smaller younger one nearby."

Of leptophylla, the same site says: "Also consumed [by Native Americans] were the young roots of the Ipomoea leptophylla, boiled or roasted. Roots over three-years-old were not eaten."

Plants for a Future says of leptophylla:

"Root - raw or cooked. Crisp, sweet and tender. Some reports suggest that the root is not very nice and was only used when nothing else was available, this is probably because old roots were tried. Roots should be no more than 3 years old, preferably only 2. Some native North American Indian tribes would use the root to store fire in the days before matches. They would start a fire in the root, wrap it up and hang it outside. It was said that the fire would keep for seven months.

A blog post at Radix turned up the opinion of a 1930s Soviet scientist that pandurata tastes "similar to Jerusalem artichokes." There's additional info and speculation here on the range and cold-hardiness of both species.

This blog post has lovely photos of the flower and plant, along with: "It is not easy to establish in gardens: it does best on sandy soils which dry out before the deep root can get to moisture most years."

The USDA plant profile warns that leptophylla is a "prohibited noxious weed" in Arizona.

SUMMARY:

None of the other sources I found referenced roots much larger than about twenty pounds, and all sources seem to agree that younger smaller roots are much to be preferred over old larger ones as food. So my dream of huge food roots slowly accumulating in unused corners of the property is dashed, or at least slightly pared back. And getting the plants established (especially somewhere that's at a remove, if only a slight one, from its original prairie habitat) looks potentially challenging. But I'll still probably get some of those seeds and have a go.

Anybody here have experience growing these roots, for food or just for the pretty flowers? Tell us what you know!

They can be propagated from seed and if you put Ipomoea leptophylla seeds into a search engine, it will generally pull up nurseries and seed companies that carry it. My thoughts are that environment is less of a factor than genetics, since it seems to be rather universally loathed in the aged roots. It might be possible to breed a variety that was less harsh to ingest, but it would mean eating a lot of really awful ones first along the way.

I'll be trying to grow this plant this year. I'll report back in this thread if I can get it established.
I'm more interested in it's potential as a drought resistant insect attractor, but I'll give it a taste too.
Seeds came from baker creek.

Awesome! I've got some seeds coming from Prairie Moon (link in original post). I think I've got plenty of insects already, but maybe that means I have not "fully internalized" permaculture ideals?

Posting this here so future searchers will have the benefit of it. The woman who organizes my local wildcrafting group has this to say about it:

This is not one to use medicinally unless you have excellent training. I might use it if I was on the verge of starvation, however I give plants that are strong medicinal's a wide berth when it come to edibility. Just the old wildcrafter in me, it demands respect.

FWIW I did plant some seeds, but the seedlings have proven very sensitive to moisture fluctuations. I have two live plants, but they are tiny and not flourishing.

I've had similar results, fairly easy to start from seed, early seedlings looked good then lost vigor when a stretch of dry weather came. We'll see, I pretty much just wanted to see if they would open up the soil with that huge root and provide another nice flowering plant for insect attraction, plus the value as a conversation piece.

My "man root" seedlings did not survive the late summer last year. However I still have seeds and will be trying again this year.

I now think that the plant might be awesome from a soil improvement perspective. I was reading a link about the root structure of sweet potatoes from this thread when I found a paragraph on Ipomoea leptophylla:

This species [(Ipomoea leptophylla] is common in sandy soil of the semiarid, central portion of the United States. It is a perennial with an enormously enlarged taproot, which is often 1 foot or more in diameter and tapers to 1 inch or less only at a depth of 4 to 6 feet. This enlarged portion of the taproot not only furnishes an enormous reservoir for food but also a storehouse of water upon which the plant may draw during a period of drought. The taproots extend to great depths, at least 11 feet and probably to twice this depth. Throughout their course they are profusely branched. Many of the branches penetrate obliquely outward or downward. Others pursue a nearly horizontal course. Many have an enormous spread, the roots running outward to distances of 15 to 25 feet or more. The surface foot of soil, as well as the 10 feet below it, is literally filled with the glistening white, brittle branches of this remarkable root system.

Wow. Holy taproot, Batman!

There was an article about Ipomoea pandurata in this month's Acres USA. The author was raving about how great the root is, if prepared properly.

Apparently it is native to Ontario, but I cannot seem to find much information as to what part of Ontario (http://nativeplants.evergreen.ca/search/view-plant.php?ID=05333). I'll try to find some seeds.