If you're not familiar with this excellent plant, you can read all about it here.
Talet has the obliging ability to form the big succulent subterranean seeds that people (read me) like to eat, as well as small hard aerial seeds which are less immediately appealing if you value your teeth, although they're perfectly edible if properly cooked. Their enamel-shattering quality means that they can sit in the soil for years before germinating and this makes them a good life insurance policy for the plant if conditions get tough. They're also pretty handy for the gardener as I've found they'll store happily with minimal attention for years, perhaps decades. You can see the difference in size between the two seed types. Same plant, two types of seeds: amphicarpy in action.
Unlike those big fat ones, the aerial seeds take a bit of persuading to germinate. You need to scarify them prior to sowing; I use a bit of sandpaper to scrape a tiny hole through the seed coat on the edge furthest away from the hilum, the plant equivalent of the navel, which is close to where the root and shoot emerge. That way the delicate bits are protected from my clumsy manipulations and once that hard shell is breached, they usually swell up and germinate fairly quickly.
I have a new variety of Amphicarpaea bracteata to try out this year. Mark Robertson very kindly sent me seeds of a variety sold by Gardens North in Canada. Sounds promising. I'm also going to see whether I can resurrect some I collected from New York State a few years ago. This is what I shall henceforth be referring to as Amphicarpaea bracteata "Saratoga Battlefield", because I collected them at the site where the British under General Burgoyne were defeated by American forces during the War of Independence in 1777. My American companions felt this was an opportunity for some gentle humour at my expense. I smiled and replied, without the slightest hint of irony in my voice, that the British, as the world's top nation at the time and bona fide bloated imperial power, had it coming. They seemed satisfied with that.
If both these new varieties grow successfully, it will be interesting to compare them in terms of vigour, yield and flowering time. The resultant plants will be smaller than those formed from the subterranean seeds, at least initially and will need a bit more cosseting in the first season to ensure that the underground crop matures successfully. I'm happy to devote that bit of extra care to guarantee success. In that case I better get on with it today, so I'm not too late starting the Radix Grand 2011 Talet Trial. Fetch me my sandpaper.