In the first part of this article (TFH Feb 2009) we explored the origins of this
somewhat rare-in-the-hobby species, tentatively identified as
Cryptocoryne cordata grabowski although Kai Witte (pers. comms.) suggests
this may just be a race of C. cordata cordata. Much is sill
not known about the Cryptocorynes of Kalimatan (and until - or if - the
plant flowers, we will never know the correct identity for sure). The
plant was traced back to a collection in 1950 and subsequent importation into Canada by one man, Charlie Drew, who has kept this population in continuous cultivation ever since.
More Photos at http://images.aquaria.net/plants/Cryptocoryne/g/GRA/c_drew/
I can't really say I understand why this plant isn't more popular in the hobby. Swords of the genus Echinodorus are nice and all, but they're all pretty much the same shade of green. Whereas this plant could pass for a sword in terms of shape and size, it is anything but green. It is olive on the top side of the leaves and screaming magenta on the underside.
And I can't say that it's a difficult plant, in fact, like most, if not all Cryptocorynes, the more you leave it alone the better it does.
Its requirements are not exactly and it will grow, and thrive, in pretty much any water and like all Crypts the most essential factor in cultivation is: stability.
That is you can have the most perfect water, identical to what's found in the wild where these plants grow, in every way. But if the chemistry or temperature or even flow rate of this water is not consistent, instead of thriving, it will be fairly miserable, miserly with growth and may even "melt" the standard Crypt reaction to sudden environmental change in any form.
I've seen lone crypts, forgotten about for a year in an otherwise unused tank. Covered, and getting light, but nothing added, no food or CO2, that did fine. Did so well in fact it's disconcerting. Let me say it again: stability.
Cryptocorynes reproduce in two ways: by seeds, sexual reproduction where both parents contribute genetic material to the offspring, and asexual reproduction where the plant sends out a runner, or a root division is made.
Left to its own devices the plant will send out a runner, or if it's a real happy camper and has lots of food, light and CO2 it will almost certainly be more productive, Leibniz' law of minimums being what it is.
And that in and of itself can be rewarding, but there are a couple of ways to speed this up. That is you don't *have* to wait for a mature plant to decide to send out a runner, you can force the issue a little by a few ways: topping, root division and microcultutre.
"Topping" is a term I think I just made up right here right now, on the spot because I'm not really sure there's a word for this and this seemed close enough. In a nutshell what's involved here is simply taking a sharp and strong knife and making a cut to separate the plant from the root mass.
Typically this is done without uprooting the plant, I don't think I'd want to try this with a plant that does not have a nice established colony of roots.
When the plant and root system are separated the plant can be floated and it will grow new roots. When it has enough that it can be planted it's stuck into the substrate and in time the roots will establish and not that much growing time is lost - it will keep going almost as if nothing happened.
Meanwhile the root cluster sitting there in the substrate should in time begin to grow new plants. That's right, plants plural, not one plant. Perhaps 4 or 5. But unlike the top half of the plant that keeps on going putting out new leaves as big as the ones it already has, the new plants growing on the root system will start out fairly small and take time to mature.
What surprises me about this is that the top half of the plant doesn't seem unduly set back. I had sort of expected the severed head as it were to start small again then, over time, work up to the kind of large stems and leaves it had before.
I'd also been surprised that the root system put up a bunch of baby plants instead of just replacing the single plant it "lost" but the more I thought about this the more it seemed to jive with the way other plants behave.
So this is one way to get a small handful of new plants without waiting for them to send runners.
Another way doesn't seem so much like decapitation although it still involves a sharp knife. This technique works better, or at least is easier to do with large Crypt species such as this one. I've done it with striking success with C. aponigetifolia (these plants, actually: http://images.aquaria.net/plants/Cryptocoryne/a/APO/submersed/ ) and noticed that the 1999 importation into Canada of plants from Morco in the Philipines had been collected from a local river that way (http://images.aquaria.net/plants/Cryptocoryne/u/UST/Morco/wild/ust3.jpg ) (Other pics at http://images.aquaria.net/plants/Cryptocoryne/u/UST/Morco/wild/ )
Cutting off a piece of the rhizome, to float it to make a new plant
More photos at http://images.aquaria.net/plants/Cryptocoryne/g/GRA/propagation/nov2003/
Often when you manage to finally procure one of these plants you might find a thick rhizome in addition to the more fine white roots you'd expect to see, and sometimes (if you're lucky) the rhizome is a couple of inches long.
Cut it off! Float it. Voilą! New plant(s). Well ok, not right now, you have to be prepared to wait a bit.
But seriously, that's it. Cut the rhizome off, about 1/2 - 3/4 of an inch below from where it originates at the crown of the plant then plant the plant as per normal. Let the now severed bit of root just float in the tank.
It's going to take a while, this won't happen overnight but if you're patient you'll be rewarded one day with a new plant growing out of the chunk of rootstock that's been floating. You can even wait long enough so that this new plant has its own set of developed roots and the plant can be carefully plucked from the original large rhizome and planted - the rhizome can now be tossed back in a tank to float and another plant will form on it, while the one you took off here and planted continues to keep on growing. Transplant shock for these is less than usual as the water chemistry and characteristics don't change, in fact I saw none of the usual "Cryptocoryne melt" when I did exactly what's described here. So I consider a myth the notion "if you disturb crypt roots the plant melts" - I think that only a rapid change to the environment can cause crypts to melt.
Separating the 6 month old plant from the florating rhizome.
More photos at http://images.aquaria.net/plants/Cryptocoryne/g/GRA/propagation/28jul05/
In addition, after a new plant has formed in the floating piece of rhizome you can carefully remove it completely and easily, plant the plant and just leave the rhizome floating and it will make a new plant again - when the plant was up to a decent size it would have put the food back into the rhizome that it used, and the whole cycle repeats again.
Planting the new plantlet
More photos at http://images.aquaria.net/plants/Cryptocoryne/g/GRA/propagation/31jul05/
This method is probably of the most use to the average aquarist, Than slicing the head off a plant, especially a rare and potentially expensive one.
This plant is no harder to grow than any other crypt. It's a hungry plant, as they all are, and while they'll grow better with CO2 (or liquid organic carbon) they'll also do fine without it. But they do require ample food, and without this they will grow more slowly. Like all crypts they abhor being disturbed, so if you don't do that, and feed them with high quality plant fertilizer made for aquatic plants, they'll just grow and grow. In a tank by themselves they will take over.
The third way of producing large numbers of these plants, and I mean large numbers, is through micropropogation, also known as "tissue culture". That's the good news, the bad news is it's decidedly non trivial, requires some fiddly bits and utterly sterile conditions. But, with this method the plant keeps dividing nearly forever, and making hundreds, if not thousands of plants from one, in a year, is not impossible; more good news.
But this is beyond the scope of this article and I've used up my quota of column-inches for today. So perhaps in a later article we can review the principles of micropropogation of aquarium plants.