Apparent Zealandia Kaka damage to Avocado Crop

Apparent Zealandia Kaka Bite Marks in Avocado 

Images of damage to Avocado Crop near Zealandia Reserve in Wellington, New Zealand. The crescent shape is consistent with bite marks from parrots on humans (1). I could not find any photos of Kaka bite marks but I can't see how it can be anything other than the NZ parrot known as Kaka from the recently instituted Zealandia Native Reserve. 

It looks like the Kaka attacked the fruit on at least three occasions separated by several weeks, but they did not destroy all of the crop, about half were damaged and in earlier years none were (the trees are young, so far bearing small crops of fruit for about four years). I get the impression the Kaka are investigating the fruit, being intelligent curious animals, having checked them out them it appears they had no further interest in them. So far it does not appear they are obsessed with eating the fruit or fruit in general but it is too soon to be certain. Avocados do not ripen on the tree and are "said to be toxic"(4) when unripe, at least to humans, it is hard to imagine any human getting any pleasure from eating the hard unripe fruit, I don't know about parrots.

Still, if this is damage from Kaka I find this rather annoying, I'm not against reserves or natives, I plant quite a few natives myself, but always edible ones where I live, alongside edible exotics. I think realistic environmentalism promotes local self-reliance through edible and useful plant and animal species near where people live to reduce unnecessary resource depletion, waste and pollution associated with transportation. Unproductive untouched reserves like Zealandia are, in my opinion, better located in remote locations away from people for the good of both people and pristine native ecosystems. 

Having a few reserves in central city areas may even be ecologically counterproductive if it people think it excuses all the damage they are doing everywhere else (a phenomenon known as the 'licensing syndrome' (2)).  Reserves may also be bad for the planet if they protects species that destroy efforts at sustainable land use such as self-sufficiency in food. I suppose Zealandia may also have a rather high carbon footprint if travel for tourist visitors is taken into account, although probably no tourists travel to New Zealand just to visit Zealandia. 

To say kaka should be able to run rampant because they are "natural" is a little like saying we should we should drink untreated water because it is "natural" (although admittedly probably not quite as extreme). Pristine wilderness is dangerous to humans despite the fact that it is often romanticized by people thoroughly insulated from it, as the environmental thinker Rene Dubos pointed out (3).

I emailed these photos to the Zealandia, Forest & Bird and the Department of Conservation, they suggested nets and planting something more desirable to distract them, perhaps that's the best we can hope for, unfortunately I find nets ugly & oppressive. They also pointed out it is illegal to "disturb" such species, so it sounds like Zealandia Kaka can destroy your property (such as home fruit trees which are much "greener" property than Zealandia I've argued) and you'll go to prison if you try to scare them off (!%#@!!???). Actually they mentioned (unsuccessful) attempts to scare them with balloons without any suggestion this was wrong so I assume reasonable attempts to scare them are legal. As far as I can see in the legislation "disturb" is only mentioned in the context of hunting protected species (as it should be), reasonable, humane, shooing of wildlife does not appear to be a concern, which seems like common sense surely.

I did recently realize the Kaka essentially ignored the bitter unripe green fruit of  a Pawpaw/babaco cross "Rainbow Valley" a few feet away from the Avocado. It appears they may have sampled them just a little (picture) and decided they didn't like them.

These unripe fruit are supposed to be edible, I eat them cooked sometimes, but they are quite bitter. Apparently birds can detect at least some types of bitterness in order to avoid poisonous plants. Seems like a (non-toxic) bitter spray might be a possibility for some crops, especially if it can be washed off the fruit when harvested & somehow made so it doesn't seep into the flesh. There does seem to be a least one commercial bird repellant spray for protecting fruit. It seems like a major long shot but perhaps sprays could even be used to prevent Kaka from stripping bark off of privately owned trees looking for edible moth larvae.

I also caught a Kaka in the act of eating some of my first crop of Loquat fruit (Eriobotrya japonica). I told it to bugger off, it obliged but was lurking around again shortly after. Interestingly the fruit had just reached full ripeness that day, apparently birds detect ultra-violet light coming from ripe fruit we can't see, though doesn't explain the damage unripe avocados, probably they are more curious than most birds. 

Go for the glow | New Scientist

I've found Loquat fruit can be picked when partly green, not fully ripe, and ripened indoors, which may also be an option but reportedly the taste is not as good (4), I think this is true but have not had enough to be sure. An exquisite tasting fruit at its best, rather like pineapple and apricot jam.  

Above : Large conifers that were killed by Kaka on private land close to Zealandia. The Kaka killed it by tearing off the bark. The trees had to be cut down as they were endangering the road below, costing over $3000. I told the city council, who self-righteously reintroduced kaka to the area via Zealandia, but they didn't offer to pay.

Kaka near Zealandia with exotic conifers they killed in background. 

Research indicates kaka are much more likely to attack certain exotic confers, Lawson cyperus, Japanese cedar and macrocarpa in particular though apparently they may attack any tree, especially if encouraged by feeding for instance. They have ignored many other non-coniferous natives and exotics in this area. 

I'm pretty sure my damaged trees are Cupresssocyparis x leylandii (close up photo below), which is a cross between macrocarpa and another conifer. So if you're wonder what trees NOT to plant in Wellington you might want to skip these. They have also killed several Norfolk Island pines (Araucaria heterophylla) nearby. They also attacked a redwood nearby.

It is unfortunate they attack such enormous conifers as they can become very dangerous and are expensive to cut down. 

I believe it has always been known kaka tear bark off of trees looking for grubs to eat, this fact was probably ignored in the self-righteous zeal of government conservation decision makers when they decided to reintroduce kaka to Wellington. 

   

References.

1.  http://forums.avianavenue.com/index.php?threads/bird-bite-photos-warning-graphic.2394/ 

2. The Willpower Instinct. K McGonigal. 2012.

3. The Wooing of Earth. R Dubos. 1980.  

Dubos argues convincingly the "natural" places we really like being in have been significantly modified by humans. Few would want to spend time in the New Zealand bush if the world's largest ever predatory eagle, the Haast's Eagle, had not been made extinct by early Maori settlers (apparently by causing the extinction of its main food source, the Moa). It is considered likely this eagle preyed on the first human settlers. Perhaps if genetic engineering advances sufficiently we should bring this species (or Tyrannosaurus rex) back  in the name of conservation, to prey on humans, because it is "natural" and "pure". Better still trying to defend yourself when they attack would of course have to be illegal because they're "native" and "pure".  

Obviously the cause of nationalistic purity has characterized well known, and once very popular, devastating ideologies such as Nazism. I'm not saying nationalist conservation zealots are as bad as Nazis but the use of reserves as something that excuses destroying the planet , while making self-sufficient homesteads difficult or impossible because of destructive protected species, may be in the end be far more harmful to humanity, despite "good intentions". 

( http://www.wingspan.co.nz/extinct_birds_of_prey_new_zealand_haasts_eagle.html)

4. Discovering Fruit and Nuts. S Lyle. 2007.

Tasty berries of some hardy epiphytic bromeliads

Small fruit of Aechmea gamosepala (left) & Quesenelia marmorata (right) which I sampled as food recently. The dark purple ripe fruit of the Aechmea was sweet, not outstanding in flavor but good. The Quesenelia was much milder and less sweet in flavor, but nice if you eat a lot of them, rather like custard. I have only sampled each a few times, on one occasion the flavor of one of them (don't recall which) was exceptional, quite complex and rich, I think this may have been when they were completely ripe, perhaps over-ripe. Figuring out the best time to pick them deserves investigation. I was surprised to find the skin of both fruit is too tough to eat, you have to squeeze the flesh out with your teeth holding the skin with your hand, probably not a plus though possibly could become habit forming like sucking on a lolly. 

Other bromeliad fruit I've tried are Neoregelia marmorata which is small, white and tastes bland but I suppose could possibly be added to dishes such as stir fry as a vegetable (the small purple flowers are also quite tasty but not produced in significant quantity) and Aechmea nudicaulis var cuspidata fruit which is small, orange and mildly sweet and pleasant.

I decided to try the fruit largely on the basis of the article Bromeliads: Edible and Therapeutic by Michael Spencer 1981 . Journal of the Bromeliad Society Vol XXXI (4). There is specific reference to Quesenelia marmorata and Aecmea nudicaulis being edible, I don't believe I ever found a specific reference to Aechmea gamosepala fruit being edible, only general statements about the genus having edible fruit as well as virtually no reports of toxicity in bromeliads except in unripe pineapples.

Although these fruit do not seem to be very noteworthy food I think they are a small but positive addition to the edible garden because the plants can grow without soil as air plants or epiphytes, producing in niches where most, if not all, more useful crops could not, so don't compete with them for space. I like to grow epiphytes attached to a house. They have tolerated winter night temperatures averaging around  + 5 C  with occasional frosts down to around  -3 C.

Spender also mentions eating the petals of Billbergia, I tried the petals of Billbergia bruauteana, they are soft enough to eat but have a slightly strange unpleasant flavor so I regard them as inedible, possibly toxic.   

Expectation Adjustment as willpower tool (for self-sufficiency)

I've tried quite a few willpower (self-regulation/self-control) techniques from books by Roy Baumeister and Kelly McGonigal and others, all quite helpful. But have found for me personally, wanting to boost my performance in efforts to be self-sufficient in food production, the best technique has been to adjust my expectations of how pleasurable and easy gardening is and should be.

I suspect most people interested in getting back to nature and growing their own food because they don't like the industrial "system"  have a rather "idealistic" "romantic" "hippy" "greenie" "Garden of Eden" idea of what gardening will be like, everything will be harmonious, cooperative and nice. This view is not limited to "greenies" this has been called the Pastoral Fallacy (7) and the Arcadian Fallacy. New Zealand was largely colonized on the basis of this myth/lie. Early advertisements in England for the country  typically said things like " everywhere pigs drunk from eating fermented wild peaches, begging to be shot" (8). Perhaps all societies since prehistory have held such beliefs about new frontiers.  So this particular adjustment may be of use to this relatively large group of people in particular. It simply means changing your expectations to accept gardening will indeed be magical, beautiful and pleasant but at times may also be ugly, disappointing, unpleasant, boring and difficult.

I don't think doing this is especially unusual, since thinking about this I've noticed people quite often talk about "being prepared" psychologically, for instance I recently read (something like) "rats make wonderful pets but they only live a few years so be prepared".  I just haven't seen it discussed in science based writing on willpower/self-regulation, so it seemed worth writing about.

"Expectation adjustment" is my term, I got the idea after noticing many of the willpower techniques Baumeister reports on already seem to exist in the military, such as tidiness and eating well (glucose believed to be the chemical basis of willpower) which reminds one of the saying "an army marches on it's stomach". So I started wondering about other thing the military do, since sacrificing your own life and killing others in battle are probably the most difficult things a rational person can attempt to do (5) and an effective army really needs to be more rational than emotional (6). It seems to me the expectation and acceptance they are going to do something extremely unpleasant and undesirable is a major factor in how soldiers are able to conduct war, or even disaster relief, imagine if they expected it to be nice*.

There is a cruel but hilarious experiment in Baumeister's book that seems to touch on this, by Mark Muraven. Runners were given equal distances to run, but some were told the run was shorter, then were told there was more to do once they'd completed this, these runners performed poorly for the remainder of the run compared with the other group (pg 34 Ref 1). This was discussed in terms of conservation of energy, but to me it is an example of being psychologically prepared or not prepared; "expectation adjustment".

I think this phenomenon may also have something to do with overcoming addiction through acceptance of the unpleasantness of addictive cravings "riding the wave" McGonigal talks about. (pg 225 Ref 2). Also ascetic people are better at difficult tasks I recently heard (3) by taking the emphasis off seeking pleasure I suppose this makes you more ascetic, temporarily.

The reality is sometimes gardening is negative, weeds and pests are competing with you and would gladly take over your niche if they could, you can't always be nice to all plants or animals. The elements don't care about you, nor does the land itself, but if you use your head and your body eventually you'll get back what you give. The aim of being self-sufficient should presumably be a degree of autonomy or independence, if seeking pleasure gets in the way of this it will have to be dispensed with for the moment. In the end you'll have far more beauty and pleasure that way.


* I'm not entirely certain adjusting expectation always fits the psychologists definition of willpower/self-control/self-regulation.  I've even wondered if this approach, at least the way I have been using it, actually makes me have less self-control as I seem to take more risks and become more daring as a result of not worrying about unpleasantness, trait normally associated with poor self-control or impulsivity. There are times when we need less self control (when conceiving a child or getting a flash of artistic inspiration) and times when we need more (when dealing with a misbehaving child or developing an artistic idea into a work of art).

Finding ways of deliberately reducing willpower/ self-control, for specific tasks for limited periods, may turn out to be just as important for a full balanced life as ways of increasing self-control, which appears to be the main, or even sole, focus of science at the moment.

At times I find the terms will power/self-control/self-regulation rather confusing anyway, for instance in a famous experiment children who resist the temptation to eat a marshmallow are considered to have more willpower than those who stared at it & usually gave in and ate it, that seems more like a technique that serves the will than actual will to me. I find adjusting expectation to be a  a way of doing something I believe I should be doing but don't feel like doing, which is all the matters to me, not terminology.



After thoughts.

Since writing the above I emailed the authors of "Self-Regulation and the Five-Factor Model of Personality Traits" in "Handbook of Personality and Self-Regulation" about my experiences. Corina Lockenhoff responded explaining that what I decided to call "expectation adjustment" sounds like what psychologists call "task framing", a term I was unaware of & will most likely use in future.

Another possible insight since writing the above is I noticed I've been working much more in the garden since moving my studio to my home, before I was catching buses across town to get to my studio. It appears the commute was draining my willpower, an example of what Baumeister & Tierney refer to when they say "pick your battles"; we all have limited willpower, we have to save it for the most important things, don't try to do too many challenging things. 

The thing is I would have never thought catching buses through town was depleting my willpower as I find negotiating the chaos of public transport and city crowds entertaining and educational. But perhaps maintaining civility in such anarchy does exactly that, drains willpower, probably a good example of what Ivan Illich called Shadow Work (9); unpaid toil and time required to support industrialism. Even more so if it is actually eclipsing our ability to do sustainable autonomous work by depleting our self-control, leaving us in a state fit only for impulsive activities, probably impulsive consumption of addictive industrial commodities in particular. Sometimes it may be a good idea to be on the lookout for seemingly inconsequential, even enjoyable, things that are depleting vital mental energy, stopping one from being able to do the important things. 

In other words, in order to do something you want to do, but find impossible, you may have to drop one or more activities from your current routine. I find this a very humbling idea, it makes you face your limits. But expecting the science of self-control to help us perform multiple superhuman feats, as I was, is probably unrealistic. Such high expectations may ironically be a symptom of the prevailing culture of narcissism/grandiosity psychologists like Baumeister (1) have criticized extensively for weakening self control.    

Finally, it also seems possible I simply became "home-centred" moving my studio home, before I was probably mainly "town-centred". "A man cannot have two masters" as a Christian friend of mine used to say, perhaps that means he also cannot have two "centres".  

References

1)Willpower. Rediscovering the Greatest Human Strength. Roy Baumeister & John Tierney 2011
2) The Willpower Instinct. How Self-control works, why it matters
 and what you can do to get more of it. Kelly McGonigal 2012
 3)  Jim Mora interviewing Marc Wilson on 'refutation' of Baumeister's ego depletion theory. Radio New Zealand 11:06 am 30/4/16
 http://www.radionz.co.nz/national/programmes/saturday/audio/201798981/marc-wilson-ego-depletion
4) Overwhelming Terror. Love, Fear, Peace and Violence among Semai of Malaysia. Robert Knox Dentan, 2008.
5) Our Inner Ape. A Leading Primatologist Explains why we are who we are. Franz de Waal 2006.
6) Civilisation. K Clark. 1969
7) The Ideal Society and its Enemies: The Foundations of Modern New Zealand Society 1850-1900. Miles Fairburn. 1989.
8) Shadow Work. Ivan Illich 1981

Pontederia cordata rhizome tasty when cooked

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 root crop to grow to me, but so far does not appear to grow fast enough here in temperate Wellington to be a major contributor to diet. It's possible I am not treating it how it likes, have not tried fertilizer yet.  

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. If the flowers are removed the very soft flower stem within is edible and tasty. It is more or less possible to eat the whole thing, the flowers and the flower stem inside as one but there are lots of very little bits that pose a bit of a choking hazard so require thorough and careful chewing.

1 ) http://www.pfaf.org/user/Plant.aspx?LatinName=Pontederia+cordata

2) http://www.hiltonpond.org/thisweek040522.html

Possibility of Pomacea as Temperate Micro-livestock.

Pictured is a tropical water snail, which I believe to be Pomacea bridgesi, which has grown to 1.75 cm over several 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. 

Even though they have remained quite small here even after several years, scientists have lately been emphasizing we don't need much meat at all for a balanced diet (if any). It might be possibly to meet dietary requirements in a small space with these snails, only they'd be more like vitamin pills than meals.  

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

    

Gordonia yunnanensis: Potential Temperate Caffeine Crop

I think the plant Gordonia yunnanensis (Syn. Camellia taliensis, Polyspora yunnanensis) 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.

It also contains theanine, considered responsible for the calming effect of tea (4).

However, while this species "usually" contains caffeine recently at least one strain, "Taliensis-akame", has been found to contain little or no caffeine (3) so scientific testing of levels of caffeine in available strains may be necessary (a few hundred dollars last time I enquired). Trying to tell by simply drinking it would be a lot cheaper but less reliable because of the placebo effect. 

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.

After a slow start Gordonia yunnanensis (pictured after one year of planting) grew very vigorously after a few years in my garden on a moderate slope, largely neglected, in Wellington, New Zealand.  It has not minded winter with night temperatures usually around 3 C, sometimes down to -5 C. It was oblivious to a very dry summer and 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. Apparently I over-fertilized them, a potential problem with the related tea plant.

I can't find anything on how the tree is usually harvested but since it is reportedly "excellent" as a hedge perhaps it can be treated like tea in tea plantations, kept at chest height from constant picking of young buds. 

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 also 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.

References

1) http://chanoyuki.com/blog/camellia-taliensis/
2) Teas, Cocoa and Coffee: Plant Secondary metabolite and Health. Crozier, Ashihara, Toma-Barberan 2011

3) Detection and characterization of caffeine-less plants originated from inter-specific hybridization. A Ogino, J Tanaka,  F Taniguchi, MP Yanqmoto, K Yamada. Breeding Science 59 2009. Available online. Fortunately this paper also reports C. taliensis can easily be crossed with C. sinensis (regular tea) which suggests considerable additional potential for caffeine production in temperate regions. 

4) 

Distribution and biosynthesis of theanine in Theaceae plants

, , 

Another interesting species mentioned in this study is Camellia furfuracea (South China tea oil plant) which appears to be the only plant known to contain theanine without caffeine, so you might get the calming effect of theanine without the stimulation of caffeine. It may have potential as a unique therapeutic and socially lubricating tea. However I can find no record of it being used as tea, it might have toxins in it as well I suppose, though I can find no record of toxicity in any Camellia. It also does not seem to be commonly available in the West or legally importable into New Zealand.  

"Wandering Jew" (Tradescantia fluminensis) Pizza

This was an experiment to  use the leaves of the very common New Zealand weed Tradescantia
fluminensis in place of cheese for a pizza, I found it delicious and refreshing. Cheese is obviously supremely delicious but not usually refreshing at all in my experience.

I have experimented with many fruit and vegetables in place of cheese, so far I've found Kale to be best, first boiled then chopped and fried then put on the pizza to be roasted with other ingredients.

I've found trying to find a plant based food or combination of foods that competes with cheese on it's own terms to be futile, doing something quite different but good in it's own unique way to be the only hope, so far that's Kale.

Trying to compete with animal products on their own terms, or to imitate them, seems to be a common mistake with vegetarian and vegan cooking.

I decided to try the "worthless" weed Tradescantia fluminensis, for my pizza when I'd run out of Kale. I removed the young and old leaves from the stems (which I had to kill in a blender before adding to my worm farm) and prepared it in the same way as Kale; boiled (to soften it), chopped, fried (for intense flavor)  then roasted with the rest of the pizza. I fried them in a generous amount of Avocado oil which I'm sure helped.

It's worth noting there appears to be only one authority who states this plant is edible, Francios Couplan Ph.D (The Encylopedia of Edible Plants of North America 1998), he recommends the young leaves cooked. I've also been eating the older leaves fairly regularly for 10 years (usually in other ways than fried, including raw). The leaves are bland in flavor, their main redeeming feature in my opinion is a crunch rather like raw onions, even when boiled.

The only real problem with using Wandering Jew regularly as food is that it does not appear to have been analysed for nutrient content, so is best used just as a novelty or last resort until this happens (if it ever happens), especially given its apparent rare use as food. Better to stick with something super-nutritious & widely used like Kale, most of the time.

It is encouraging, however, that the similar Commelina nudiflora from the same family has been analysed and suggested as a cheap source of Vitamins C, B3 and B2 as well as other macro and micro nutrients (1).

1. Nutritive and Anti-Nutritive Properties of Boerhavia diffusa and Commelina nudiflora Leaves. C.O. Ujowundu , C.U. Igwe , V.H.A. Enemor , L.A. Nwaogu and O.E. Okafor.
http://pjbs.org/pjnonline/fin689.pdf