Yacon - The Kentish Connection

That gladiator's net is closing on the mystery of the yacon hybrids.  Frank van Keirsbilck told me that the unidentified pollen parent was a Smallanthus that came from seeds provided by Ulrike Paradine. These were from plants that have been growing happily for a number of years in her garden in Kent. I contacted her and she kindly gave me a few more pieces of information and some pictures of her plants. Cop a look at these:

Image courtesy of Ulrike Paradine

Image courtesy of Ulrike Paradine

There's no mistaking the similarity of these images to the yacon hybrids. She collected the seeds (OK, you pedants, cypselae) herself in Costa Rica.  I did a bit of intensive interwebbing and my trident speared three possible candidates for this unfolding paternity suit:

S. latisquamus
S. maculatus
S. riparius

All three species are found in Costa Rica. So far, so good. Of the three, S. riparius is found from Central America to Northern Bolivia and is considered to be similar to and maybe able to hybridise with, S. sigesbeckius, one of yacon's putative ancestors.  So, as far as I'm concerned, it's a possible thumbs up for S. riparius as our mystery species. Or, as toga party afficionados will never cease to explain, that should actually be a thumbs down.  If anyone out there with first hand knowledge of the genus Smallanthus would like to chip in, please do.  I could be wrong.  I usually am. 

More interesting information from Ulrike: the plants regularly set seeds in Kent and not only that, she has had self-sown seedlings appearing from time to time. Her plants have often overwintered outside in her garden. They don't have the big storage roots of yacon, unfortunately. Despite this, these strike me as exactly the kind of robust, sturdy, adaptable traits we need to incorporate into the Radix yacon breeding programme.  You didn't know there was a yacon breeding programme at Radix?  There is now.


orflo said…
Last niht we had light frost, and I couldn't protect everything, so I decided to give up on some of these smaller yaconhybrids. I did dig some of these frozen plants up this evening, and the roots were very small, 1 cm thick at the most, and a sort of creamy-white colour. I had a quick taste of these roots and these were actually very tasty, very spicy, way better than an uncured yacon root. But way too thin and small. However, I only did dig the smallest plants, and the bigger one of these three had some thicker roots, so maybe the really big ones will have something more promising. I did find some seedlings of that unknown polymnia as well, but very small ones. They probably couldn't germinate in spring because of the drought. I still have a whole bag of seeds of that smallanthus species, collected in 2009. These could have crossed in a natural way with yacon, off course, not every yacon flower was covered.
The yacon-hybrids showed no sign of producing some small propagation tubers on top of the roots, but this could be because they were a vey small size. They do have a tendency to form new shoots on the stem just above the roots.
orflo said…
By the way, good searching there!!!
Mark said…
I agree with orrflo, very good sleuthing
Rhizowen said…
Hi Frank

My plants have all been frosted now too, so there won't be any seeds this year.

Elementary my dear Mark
orflo said…
maybe some of my plants will produce some seeds, they're still alive, a bit of frost on the leaves, but some were covered and are doing fine. And the weather forecast is better...