A Flurry of Flowers

It's now over a month since the first flowers appeared on one of my oca seedlings - RX0916, to be precise. The weather has been against us (that's me and the ocas), but has now improved to the point at which wan sunlight filters through leaden skies on occasion and allows me to see my own hand at arm's length. Poetic licence, maybe, but cloud cover has been unusually dense over the last two months and the rainfall exceptionally high. We've just been slapped by the dying gasps of Hurricane Bill as the final hurrah to a supremely indifferent August. There's a distinct autumnal chill in the air these mornings; this is all very well, but it would have been nice to have had a bit more of the azure skies and blazing sunshine that we associate with summer before slipping inexorably into the no man's land of November and beyond.

No matter - an increasing number of the other oca seedlings are starting to flower, so I've decided to try and ascertain what kind of stylar arrangement each individual has. This should make it a little easier to cross pollinate them and produce more botanical seed, ready for a further round of sowing, growing and selecting.

As of yesterday there are 15 seedlings in flower, with another four likely to do so in a few days.

Of the flowers I have examined so far, two stylar morphs are present. Consulting my CIP oca descriptors I find these are 1) brevistilia and 2) mesostilia - that's short-styled and medium-styled. I haven't seen any long-styled flowers yet, although I'm pretty sure that some of the potential parents in my possession display this trait. The following image will hopefully make apparent the differences.












The flower on the left has the stigmas positioned at the base of the flower, below both whorls of stamens and is thus short-styled. The flower on the right has the stigmas between the whorls of stamens and is therefore mid-styled.

Breathless update: I've now discovered a seedling (0905 to be precise),with the third type of flower, called in CIP lingo "longostilia", or long-styled. I didn't have my camera with me, unfortunately.

So far the short styles outnumber the medium styles by roughly 2:1, which seems strangely significant and will no doubt prompt me to go and do some research on the mechanisms of inheritance of heterostyly in oca. What better way to spend the August Bank Holiday weekend?

Due to the attention lavished on my little darlings, (perhaps I should call them ocarinas), I didn't get round to planting the tubers of the other varieties until a bit later. So, although some are starting to form flower buds, they're not as precocious as my own little brats. I've got a fairly good idea of which varieties are the likely parents of my brood, so I'll be interested to see what floral arrangements they have (and I'm not talking ikebana or wedding bouquets).

Some seedlings have reddish sepals, as seen in the following photo:

Another distinguishing characteristic is the presence or absence of little blotches of purple at the base of the leaves where they join the stems. In my other varieties this seems to be carried over into the tubers as dark marks around the eyes. Oca tubers are, like potatoes, modified stem tissue rather than true roots.

Some of the plants with the red sepals have the purple blotches, others don't. From this I deduce that the two characteristics are inherited separately. Whether sepal colour has any influence on tuber colour remains to be seen. If I can avoid my notebook going mouldy or being devoured by slugs, I should have an answer to this by late autumn.

Here's a stem with purple marks at the leaf axils and reddish sepals (honest).

The reclining pose is due to the effects of wind and rain and the twine is an attempt to stop it flopping any further over its comrades. What is it they say about the British climate? Ah yes - one of the best for growing crops and the worst for harvesting them. I'm not even sure about the growing bit any more.

And this is one without blotches, but possessing purplish sepals. Still vertical - so far, thanks to the sheltering embrace of the maukas.

I've noticed what appear to be a couple of fertile pods developing on 0916 and 0917, so I'm keeping a close eye on them. If there's anyone out there who is studying their own pod-laden ocas with similar excitement, it's worth sharing a few tips. The first thing to be aware of is that oca pods are explosively dehiscent, that's to say they pop open and forcefully scatter the tiny seeds. You can forget trying to find them afterwards. Like an overprotective parent, I feel they are a bit too precious to be allowed out on their own. The only answer is to individually bag the pods or harvest them when the seeds are ripe, or nearly so. Oh for the simplicity of big, seedy potato fruits.

Back in 2007, I found bagging the pods individually exceeded my levels of dexterity, raised my blood pressure and expanded my range of expletives. It also threatened to damage the very pods I sought to protect. I decided to opt for the nick-of-time harvest method instead, storing the almost ripe pods in a Petri dish. By placing said Petri dish close to my ear, I was able to hear, on more than one occasion, a Liliputian ping, as a pod ripened and then shattered before my very eyes - I mean ears. If, as I hope, a multitude of pods are formed this year, I may revise my options and try and bag the flowers.

Here's a ripening pod on 0916. Sometimes the seeds are visible through the walls of the ovary and persistent calyx as little bumps. Each bump consists of a seed wrapped in a pale green fleshy aril. Looking at this makes the seed appear under ripe, but the pod may actually be close to dehiscence. Beware!

Just after this picture was taken, we were hit by more wet and windy weather. I could hardly believe it when this little pod, pregnant with possibility, was from its mother plant untimely ripped. Oh calamity. A bit of diligent searching revealed the squashed and soggy pod lying beneath a pile of sprawling oca stems. And there, like a pearl in a pulverised oyster, sat one tiny seed.

You can forget about your new season Beaujolais and associated hullabaloo - to me this event has much deeper resonance. Excuse me mixing my drinks, but here's to Chateau Mouton Radix 2009 - let's hope it's a good vintage.

From what I've read, the original Radix pollination method, involving shoving one flower into another, can be improved upon. I shall go away and see whether I can develop a method with a little more finesse and a little less, well, brutality. I'll keep you posted.