Wednesday, April 27, 2016
Picture: Pontederia cordata var lanceolata (a larger form) with boiled rhizome sections.
I found the peeled rhizomes of the aquatic plant Pontederia cordata (Pickerel Weed or Rush) quiet tasty after boiling for 5 minutes then frying. They were pretty firm, perhaps they need longer boiling, tasting mildly like mushroom, pate and mud, in a good, interesting way.
I am not aware of any book saying the rhizomes are edible but one says all parts are (see 1). I tried them anyway as I've carefully sampled every part over many years and it seems utterly non-toxic, the parts known to be edible taste the same as all other parts (raw), much like the water the plant grows in. Also no part has ever been reported toxic. There are several internet sites saying the rhizomes have been eaten, such as Hilton Pond Center which states the rhizomes have been stewed as a potato substitute (2). Also various birds eat the rhizome along with other parts.
This looks like a very easy, reliable, at least moderately productive, root crop to me.
I started growing this aquatic plant in tubs because I wanted the edible nut-like seeds, however they do not appear to be produced here in New Zealand, perhaps because the required pollinator (1) is absent. I've found the supposedly edible young leaves and very young stems to be very disappointing, tiny & sparse, but have tried the small flowers, better, basically tasting watery too.
1 ) http://www.pfaf.org/user/Plant.aspx?LatinName=Pontederia+cordata
Monday, April 25, 2016
Pictured is a tropical water snail, which I believe to be Pomacea bridgesi, which has grown to 1.75 cm over two years, possibly less, in an outdoor aquatic plant tub in temperate Wellington, New Zealand (hardiness zone 9). This species is harvested for meat in tropical and subtropical regions (1), no doubt when it has grown to its much more impressive full size of 4-6 cm.
Growth appears to be dependent on heat, seems to be very slow in winter, much faster in hot weather, and it has been an unusually long, hot summer. Based on reports of growth rate in tropical countries growth is much slower here than there, but I will be watching with interest the progress of this and around 100 babies, in the coming years. At this stage I'm only reporting on them as a potential temperate micro-livestock, since I was so surprised they even survived and reproduced outside not to mention one growing to an almost respectable size.
Slaughtering snails for meat might raise fewer ethical and psychological issues for people who would normally avoid slaughtering complex animals for meat. I'm not sure I'll ever be slaughtering them for meat myself. I'm more interested in the potential for others who want to produce their own meat, especially in squeamish suburbs (or perhaps even apartment blocks, they could conceivably grow in tubs on balconies) .
Another advantage is it appears to require little care or feeding, I have it in tubs with edible aquatic plants, such as Nymphaea odorata, and Aponogeton distachyos, they seem to mainly eat the algae growing on the plants, though the Aponogeton occasionally looks pretty mauled. There might be potential to supply them with foods that make them grow faster.
An additional advantage is they don't need elaborate containment structures like gourmet land snails, they seem to stay in, or very near the water. Though it appears they can attach themselves to animals that visit the water and escape that way, presumably this explains how a number ended up looking quite happy in my dog's water bowl some distance away inside!
A disadvantage is they often lay eggs on, and cling to the underside of the edible aquatic leaves I harvest for dinner. It can be fiddly getting them all off. I understand some water snails have extremely toxic eggs, I believe these are species with very brightly colored eggs, showy displays are usually a sign of danger in the animal, plant and human worlds. The eggs of my snails are transparent, indicating they are "hiding" because they are non-toxic, probably I have eaten a few of them by accident with no noticeable effect. But plants are more my area than snails, I strongly encourage doing your own research or find an expert on this subject.
Another disadvantage is they would be difficult to remove from a tub or pond once established, I tried with chlorinated water which kills many fish, they loved it. Perhaps a traditional fish toxin like saponins from various plants would be worth a try, otherwise complete draining might work, but they actually have lungs as well as gills so might even survive that, at least for a while.
I discovered they could survive outside entirely by accident, I was raising them indoors in a tank, it didn't seem to be going well, the older large ones, purchased at a pet shop, kept dying. So I gave up on the project and dumped the water, containing a few tiny baby snails, into some of my outdoor water plant tubs expecting that to be the end of it. Much to my surprise I noticed eggs everywhere shortly after. So they are able to go through their full reproductive cycle when very small, they do not need to grow large for this.
1) Apple Snails in the Aquarium. Dr G Perera, J Walls 1996
Friday, April 22, 2016
I think the plant Gordonia yunnanensis (Camellia taliensis) could be a good source of caffeine for home gardeners, perhaps even orchardists, in temperate climates such as Wellington, New Zealand.
This attractive tree has long been used for tea, collected from the wild, in the Yunnan Province of China (1). It has only recently become widely available in the nursery trade elsewhere, it also appears that it was only discovered to contain caffeine as recently as 1984 (2). Presumably communism kept it unavailable and little known to outsiders until very recently.
So far there seems to be little interest in this plant as a caffeine crop, which seems a little surprising given the economic importance of "mildly" addictive caffeine, found in very few plant species. As far as I'm aware it has been marketed exclusively as an ornamental not a caffeine/tea source in the nursery trade. I am also not aware of any books or sites recommending it as a caffeine source for home gardeners, only sparse scientific texts and the odd traveler seem to refer to use as tea. Conceivably the recent name change from Camellia taliensis to Gordonia yunnanensis has not helped, I'm not aware of a reference associating the new name with caffeine or tea.
The plant pictured has been in my garden, largely neglected, in Wellington, New Zealand, for about a year. It has not minded winter with night temperatures usually around 3 C, sometimes down to -5 C . It also seemed to be oblivious to a very dry summer and below average, fairly hard clay soil. Some other plants I gave much more care to did not do so well, losing up to half of their leaves. Perhaps I over-fertilized them, a potential problem with the related tea plant.
I have not had the plant long enough to judge how productive they are, growth was impressive in spring but so far very slow at other times. Determining productivity is my main objective in the next few years.
I have not drunk it a lot yet but tried a few cups, it seemed better than standard (Camellia sinensis) tea to me which I don't like much because of its astringency. This tea does not appear to be very astringent, drunk on an empty stomach (without milk or lemon to counteract the astringency) I only got very mild if any symptoms of astringency that I get from tea on an empty stomach, such as feeling of, or actual, vomiting and dry mouth. I suppose it's possible it was just too weak because I didn't prepare it in the correct/traditional way whatever that is ( I dried one large leaf on a sunny window sill for a few days then poured boiling water on it and let it sit for a few minutes).
It doesn't seem to have a strong taste of anything to me, a bit like mild tea when dried. There are comments on the net saying it doesn't taste that good, to me this is a minor problem if you think producing your own caffeine is more desirable than getting the third world to grow it for you and having corporations ship it around the world for you. Plenty of tasty things could be grown and brewed with it to improve its rather bland, mild flavor if that's an issue. In my opinion almost any flavor associated with something addictive starts to taste mighty good over time, look at beer, tobacco or wine.
I chewed the raw flowers (without swallowing) thinking they might be edible like the related Camellia japonica. After about a minute they produced a kind of burning sensation at the top of the mouth right at the back lasting about five minutes, tangy, perhaps like oxalic acid multiplied many times. I infer from this they are not edible raw. It is conceivable they'd be edible if dried and cooked as is apparently always done with Camellia japonica but I won't be trying that any time soon.
2) Teas, Cocoa and Coffee: Plant Secondary metabolite and Health. Crozier, Ashihara, Toma-Barberan 2011