Flemingia procumbens: Soh-phlang from far-flung Shillong

That's Shillong, capital of Meghalaya, a state in North Eastern India, nestling in the foothills of the Himalayas, in case you didn't know. Sometimes it's nice to escape the gravitational pull of the Andes as the one true source of unusual roots and tubers. In that contrarian spirit, meet soh-phlang, a bona-fide root crop which most people have never heard of.

Meghalaya is a fascinating state, with all sorts of interesting edibles, both wild and cultivated. Strangely, the area is mainly Christian, thanks to the efforts of Welsh missionaries who arrived in the mid 19th century. Meghalaya means, apparently,  "abode of clouds". I don't know whether it was the familiarity of the area's heavy rainfall that attracted the Welsh - Cherrapunji and nearby Mawsynram vie for the title of  wettest place on the planet; their annual rainfall totals of over 12 metres make Blaenau Ffestiniog, Wales' wettest town, seem positively parched in comparison.

I first became aware of soh-phlang in my undergraduate days, when I was frequently to be found between the library shelves, reading copies of Economic Botany. I still reckon it was a better use of my time than lurking behind the bike sheds for a surreptitious cigarette or some other nefarious activity. I forget what I was supposed to have been studying at the time, but the memory of soh-phlang remained; in the decades that followed, I saw the odd tangential reference to its cultivation, both in its heartland  as well as other places - Vietnam springs to mind.  It's worth mentioning that most of the literature associated with this species uses its old name, Flemingia vestita. Those meddling botanists - they just can't leave well alone. 

Soh-phlang is a small trailing legume with crisp, white root tubers, which are usually eaten raw and have a nutty flavour. They're often dipped in a sesame paste before consumption and have a high protein and phosphorus content. Their skin, which is easily removed by hand, has a reputation as an anthelmintic; should you be troubled by flukes, just reach for the soh-phlang peel - it's all about the genistein, apparently.

Until fairly recently, soh-phlang was collected from the wild, but it has now become quite a popular crop and has been incorporated into the jhum shifting cultivation which is practised by the Khasi people who live in this area. It fixes large quantities of nitrogen courtesy of its root nodules and has extensive mycorrhizal associations; with these abilities, soh-phlang helps maintain soil fertility, as well as providing farmers with a valuable source of income.

There is precious little information on how soh-phlang is cultivated, although I seem to remember reading somewhere that small seed tubers are usually planted in the spring and yields of up to 3000 kg/hectare can be obtained. Maybe if the summery weather holds, I can try intercropping them with potatoes as is done in Meghalaya. Or, perhaps, better still, with oca. The plants themselves do seem a little like diminutive ocas, with neat trifoliate leaves.

The best illustration of soh-phlang available to mere mortals seems to be this one. It certainly gives a sense of the trailing stems which account for the specific epithet, procumbens. I'm indebted to Anne Patrie, an ethnobotanist who is conducting research in Meghalaya, for drawing my attention to it.

But that's the wild type F. procumbens; domesticated plants tend to be more bushy and upright, which is how mine appear.  Flowering usually occurs after the monsoon season, sometime in the autumn, which suggests that day length sensitivity could be an issue if seed production is required. I haven't yet seen any nodules on the roots, which might indicate that the correct rhizobia are missing. The plants aren't exactly romping away either, perhaps a further indication that the roots are lacking the right symbiont.

Whether soh-phlang will prove to be productive in our climate remains to be seen.  Although the weather is warm and humid at the moment, it has been downright cold for months and I haven't dared try my plants outside. I suspect that our usual frequent rainfall will suit it fine, but maybe average summer temperatures are too low. That's a pity, because I've been been doing some fusion food fantasising: I just can't erase the image of soh-phlang dipped in Cornish clotted cream from my mind.


Emma said…
Is it just me, or does it have a whiff of a clover about it?
Rhizowen said…
The leaves are distinctly clover- like in appearance, Emma.

Darby said…
I would love to grow Sohphlang! Do you know of a source so that I might purchase it?