Numb Fumbling 2: Sagittarias Rising

The weather has been slightly cooler of late, so what better time to plunge my hands into the icy cold, muddy waters of the Sagittaria buckets to examine the yields. This is considerably less pleasant and more painful than oca harvesting. Perhaps the only thing in its favour is the natural buoyancy of the Sagittaria tubers*, which once released, bob to the surface and can be scooped up; ocas tend to stay put and require sifting, no easy task in our sticky clay soil. I'll hold fire on that manicure until the harvest season is well and truly over.

This year I grew two varieties of arrowhead, S. latifolia, the wapato and chi gu 慈菇, a  Chinese arrowhead variously described as S. trifolia var. edulis or S. sagittifolia var. edulis - the taxonomy seems somewhat confused. In any case, the latter is a cultivated variety, which showed no signs of flowering, but was noticeably bigger in all its parts. It could be that it's a triploid, with an extra set of chromosomes; this might account for its larger size and apparent sterility. This is a not-uncommon occurrence in the world of root crops, being found in varieties of achira, hopniss and ulluco as well as some types of potato, to name but a few of my target species. The main advantage of this is that the plants wastes no time and effort on producing seeds and concentrates on vegetative reproduction; this is great if it leads to big fat tubers. The problem comes when conditions change and you want to breed varieties to meet the challenges of new pests and diseases, for example.

Other research suggests that the application of GA3, a plant growth regulator, will encourage flowering and seed set in some varieties of Chinese arrowhead. I can foresee some great fun crossing and selecting various arrowheads to create my very own locally adapted variety. All I need is time, space and an independent income. Or perhaps you'd like to take the project on?

I grew my plants in builder's buckets which are probably a little too small for a decent crop, but the chi gu tubers are noticeably bigger than the wapatos. To be fair, I didn't thin out the wapatos very much much this spring, so they were probably a little congested and starved of room; as the old refrain goes, next year is going to be different.

Here are the biggest of the chi gu:
Chinese arrowhead

And some wapatos for comparison:

Chi gu is a favourite New Year's food in China, often being served in the form of deep fried slices. Lovers of rude vegetables will be delighted to discover that the Chinese consider the tubers with attached sprouts to resemble a baby boy's genitals and this is apparently auspicious for family fecundity. I shall bear that thought in mind next time I'm harvesting them and accidentally knock off a large, firm shoot.

2013 may have been the unofficial (and unwelcome) year of the horsemeat scandal in the UK, but I notice that the Chinese Year of The Horse is galloping towards us at the end of January 2014. I'm thinking this might be a good time to explore culinary convergence of an "everything with chips" kind, using my wapatos and chi gus as a spudstitute. In the meantime, I wish you all a Happy New Year.

*Rather than practice my usual boretanical pedantry, I have elected to use 'tuber' for what are, technically speaking, turions.


orflo said…
your chi gu seems to be way bigger than mine, which are more marble-sized. They come from Japan, and require lots of heat to start growing. Oh, maybe I just don't give them enough space (about 30 liter), or there could be some climate adaptation, if yours should come from cooler areas, comparable to hog peanut or apios
Rhizowen said…
Hi Frank

I wonder whether the very warm weather we had in July might have had a favourable effect on their development. I was certainly pleasantly surprised.
Anonymous said…
Hi there,

Can you let us know where you sourced your chi gu from?

Your chi gui tubers certainly are large - perhaps twice as large - compared to the wapato tubers I grew this year.