The Root Less Travelled 1) More Peas Please - Aardaker and Caremyle

Despite my enthusiasm for root crops (and other plants) less well known, I have to accept that some minor crops are minor for a reason. Then again, I earnestly hope that, by some miracle, they can discover their own greatness. If not, I'm happy to try and thrust it upon them unbidden.

Here's a couple that, at present, fit the minor description, but are waiting in the wings to cast off the yoke of obscurity - perhaps. Like hopniss (Apios americana), they're legumes, but this time more closely related to peas than soy beans. Even more closely to sweet peas, in fact: they're both perennials in the genus Lathyrus. They fix nitrogen , as is evidenced by the large quantities of nodules attached to their roots. They have a long history as food plants and they're attractive and easy to grow (with one caveat).

These are the roots of Lathyrus tuberosus, the tuberous pea or aardaker, which is, coincidentally, the name of one of my followers, who is possibly Dutch. I grew these a couple of years ago:

Aardaker means "earth nut" in Dutch, or so I've been led to believe. The "aard" is obviously as in aardvark, so that's OK; don't know about the "aker" though. If I'm wrong, perhaps "Aardaker" would care to reveal her/himself and put me straight. Other names, in two other well-known European languages (guess which) include: macusson, tanotte and the somewhat prosaic Fyfield pea. Fyfield in Essex is the area in which the plant is most frequently naturalised in Britain. It is a pretty trailing plant with lovely bright pink flowers. It has the added bonus of producing some really delicious tubers. In my haste to get at the tubers I somehow forgot to take any pictures of the flowers at the right time. For another take on this plant, have a look at Catofstripes' experience with it.

Unfortunately the limacine reapers that infest my plot seem to find the foliage more attractive than almost anything else, producing characteristically tattered effects: Slugs one, aardaker nil:
This year's tuber, if it can be afforded that title, wasn't worthy of even the most flattering photo makeover. I'm a bit sad that I've finally run out of seeds - I rather fancied having another go this year.

What puzzles me is that we have two other members of the genus Lathyrus growing wild locally: Lathyrus sylvestris and Lathyrus linifolius. The former is a vigorous perennial that can be found trailing over the cliffs near the sea. Perhaps the extra salt deters the slugs and snails from defoliating it with the enthusiasm they show for aardaker. Maybe it's just that bit more vigorous or doesn't taste so good. It has a fibrous root system and produces quite long underground shoots, but no tubers that I'm aware of.

Lathyrus linifolius, also known as the bitter vetch is, from a root crop enthusiast's point of view, an altogether more interesting prospect. It seems to survive the depradations of molluscs with aplomb. That's a good start here at Slug Central. It has fairly upright stems, which, unlike the preceding two species, have no functional tendrils. It's a tidier plant, more suited to standard gardening practices. And guess what - it has tubers which have a long history of use as food and medicine. Like the effects of a not-so-wee deoch an dorus, this is where things start to get a bit hazy. It was, supposedly, used as a famine food in the Scottish highlands and islands, but not exactly for sustenance; consuming the tubers of caremyle (one of its Gaelic derived names) conferred upon the eater the ability to exist without hunger for weeks - it was claimed to have a powerfully suppressive effect on the appetite. Maybe it was just a practical way of dying without the added inconvenience of stomach gnawing hunger pangs.

Sounds like the ideal slimmer's food for blubbery Britons, growing, not in the Amazon rainforest or Andean Peru, but on yon bonny banks and braes. Surely someone must have done some research on this? It turns out they have. Back in 1670, Sir Robert Sibbald, one of the founders of the Edinburgh Botanic Gardens, grew it and referred to it as "Herba Scotica Miraculosa" on account of its ability to quell appetites, including his own. Just a little more recently (2005 onwards), the Agronomy Institute of Orkney College have been growing the plant, although I don't know whether they've actually harvested it yet.

In any case, the tubers, known as "knappers", were said to have a sweet, acidic taste and were dug up and dried before consuming or being added to the aforementioned dram to make a restorative tincture.

My plants cannot be said to have been high yielding so far:

Yes that really is a tuber, nestling in amongst the roots, but not a very large or appealing one. I haven't dared eat it yet. I'm still unclear whether caremyle is a one hit wonder as regards its tuber, or perhaps a mature individual produces several. My curiosity remains unsated, even if my appetite takes a nose dive when I finally get to eat it.

Apparently Nell Gwyn, that well known orange vendor and popular bedtime squeeze of Charles II, was fed caremyle tubers by the king to keep her in shape. I don't know whether this picture shows her before or after chewing her caremyle:

There are other images available, which show more of her flesh than this. Again, it's hard to draw any conclusions about the possible influence of caremyle on her body mass index. I can't quite make out whether the posy with which she coyly poses contains any caremyle, or maybe that blasted sheep ate it.

It seems to me that these two species of Lathyrus, aardaker and caremyle, have some really interesting properties. Like Batman and Robin they're a dynamic duo, with complementary qualities. But might they be even better combined? I'm talking about crossing the two species to create, ker -pow! a delicious underground confection that leaves you feeling full up for days, maybe weeks. This sort of inter-species hybridisation has a long and distinguished past in the development of new crops, witness wheat, oilseed rape, coffee, cotton and tobacco - and let's not forget dear old oca.

As far as I know, both L. tuberosus and L. linifolius have the same number of chromosomes, 2n = 14. They occur in totally different habitats, with L. linifolius found on acidic soils, whilst L. tuberosus is generally found in limestone or chalk soils. Chances are they would never meet in the wild. Matchmaker, matchmaker, make me a match. Lathyrus species don't, apparently, cross very easily, so it might get a bit technical and frustrating, involving stylar amputations, embryo rescue, polyploidisation and God knows what else. Still, I'm game for a laugh - how about you?


orrflo said…
Nice post , as usual, Owen. The old word 'aker' has some meanings, the first and most important meaning is a bucket, which has no relevance here, but another one is acorn, and I think that's it, so aardaker just means acorn of the earth, it seems that everything growing on trees did get an equivalent in the earth as well, earth chestnut, earth almond, a French name for yacon is 'poire de terre', earth-pear, another Flemmish word is aardappel, that's just a potato ('earth-apple') , and so on...
Patrick said…
Someone gave me some aardakker this year, which has since shrivelled up and died do to my neglect, so I probably won't get a chance to try it this year. I think in general my preference is for plants that have been at least a little domesticated, and your post sort of confirms the reasons for that.

I know a lot of people really enjoy eating wild plants, but an awful lot of improvement can be had with just a little breeding work...
orrflo said…
aardaker should be kept moist, preferably covered with earth. They do stand very low temperatures, so keeping them outside is no problem. This is actually one of these plants that seem to refuse breeding efforts (skirret is another example of this),
although I have an old book here that mentions aardaker had some selected varieties that were mainly grown in Zeeland, the Netherlands. None of these varieties, if they ever truly existed seem to have survived..
Rhizowen said…
Hi Frank
I did wonder whether the aker bit might have been acorn, but the word that came up was eikel. At least I was fairly close. That's really interesting about the supposed varieties of aardaker in Zeeland. I'd be interested to know how they differed from the wild plant.

It might be possible to collect seeds from differing parts of Lathyrus tuberosus' range, compare them, cross them and try and get some diversity into the resultant progeny. If someone would like to try growing 10,000 seedlings, I'm sure we might see some real variation in tuber size. Most of the time I think we're just sampling too few plants. It's a good plant - delicious, nitrogen fixing, hardy, with a long tradition of being eaten over a wide geographical area. It deserves to be domesticated..

Hi Patrick
I lost virtually all my aardaker tubers when I allowed them to dry out, even though they were in compost at the time, so I sympathise.

Hi Mark - I try to have fun, but I do get a bit upset when I lose my plants.
Mark said…
Hi Rhizowen
I understand, I hate losing plants I have grown. Your plan for breeding L.linifolius is sensible and I agree that people are probably not sampling enough to see the variation in tuber size that could be present. Crossing the two species of Lathyrus seems potentially very interesting. So I wish you good luck. Maybe someday someone will pay me just to do such an experiment. Although I doubt it, sound like too much fun compared to the PhD.
Rhizowen said…
Hi Mark

I think we should organise a whip round and get you started on this as soon as possible.

Is anyone prepared to match the £5 I'm now pledging to Mark for the Aardaker-Caremyle project?

I forgot to mention in my post that not only are the two species geographically isolated, but also temporally - L. linifolius being a vernal flowerer and L. tuberosus flowering later on.
Mark said…
Thanks for the laugh. The last stages of a PhD are not fun, so any laughs are much appreciated
Rhizowen said…

The offer still stands post PhD
Alan said…
Thanks for the tip about Gardens North. I'm just about to order some Lathyrus tuberosus and a heap of other stuff. I've also got some L linifolius so I might have a go at that breeding project.
Rhizowen said…
Hi Alan

Thanks for your comment. Good luck with your Lathyrus breeding - do let us know how you get on.