Orchidarium 5

The ongoing saga of adapting a purchased Wardian case as an intermediate temperature orchid growing case, my orchidarium.

The configuration in the picture is temporary, with plants more or less hanging from the roof or sitting on the bottom in places that will help me gauge light preferences. The large piece of grapewood to the left is in its final position and has one plant (Specklinia grobyi) permanently placed. 

The lighting is now solved, after some fits and starts. A combination of 40 watt and 90 watt LED lamps gave too MUCH light, so I have scaled back to 2 of the 40 watt lamps (Kessil Tuna Sun A160WE), both shining through a glass plate in the roof so that waste heat stays outside the case. Happily, the structural parts of the orchidarium are now complete - vent fan, internal fans for air flow, and lighting. I do all the watering by hand with a pump-up spray bottle; the case is small and this only takes about one minute. I do the main watering in the morning and a quick misting at night when the lights go out. Almost all of the plants are now thriving.

I have several large pieces of rot-resistant grapewood burl (bloomsandbranches.com) that are beautifully natural and have a nice texture for orchid roots. The source says that they are sandblasted but otherwise untreated. You can see some of them in the picture above. I played around with various methods of situating them in the case. I tried bolting them together and sitting them on the bottom, but that isn't easy because the wood is so irregular and is filled with unexpected pockets and layers so screws don't hold well. I did get some of the core parts bolted together to make a base. I tried just leaning them up against the glass, but that is not very stable and limits the way they can be arranged. Finally, I stumbled on using the fact that the roof of my case is steel and that very strong neodymium magnets are inexpensive: I am hanging the grapewood from magnet hooks attached to the inside of the roof. My mounting wood is itself epiphytic! I drill small holes near the top of the wood and thread wires through them and the hooks. Black nylon-coated fishing leader wire is perfect - strong and nearly invisible. This method is simple, easy, and very flexible because I can move the magnets around and change the lengths of the suspension wires easily. If you have a case that does not have a ferromagnetic roof, you could achieve something close by drilling holes and inserting hook bolts or stringing guy wires that you can hang things from. Grapewood burl is fairly light but a piece can weigh up to a few pounds, and then there are the plants and water weight, so you would need a roof with considerable strength. Fortunately mine came with that.

Mounting orchids directly to the grapewood is finicky work though fairly easy. It is awkward threading monofilament line around the pieces of wood when in place, and tying knots in that stuff seems to require three or more hands, making me wish once again that we were bipeds evolved from hexapods. An alternative is to use Super Glue, but that makes white deposits that are glaring and very hard to get rid of or camouflage. The monofilament is hard to see and when the plant is established it can be removed. Partly because I am not very patient with finicky work, but also because the final mounted position of the plant ideally is gotten right the first time, I am doing this part very gradually. Okay okay, I have mounted ONE plant directly to the grapewood so far. But it is lovely!

The light intensity across the cabinet is extremely wide ranging, which is good for plant diversity but challenging for placing individual plants. What seems to be working fine, but is very slow, is hanging or sitting a plant on the original mount or pot in some location that I think will work, and then waiting a month or two to see if it thrives. I have found that most of the cloud forest orchids I have in the case get a purple flush or spots on their leaves well before getting dead sunburn patches as I am used to for windowsill plants. One plant (Lepanthes gargoyla) went from being dark green to bright purple in about a month. Often the purpling starts within a day or two. When that happens, I back off a bit until I get a spot where the leaf color looks correct for the species; some are supposed to be purple, but not many. I have tried to use a cell phone light meter but damned if I can get the readings to match what the plants are telling me. I have spots where the light meter says 200 footcandles and a plant that is said to like 500-1,000 footcandles turns purple within days. I don't think my light spectrum is weird - these lamps are designed for plants and the orchids once situated well are clearly happy. I think the cell phone light meters are inaccurate at low light levels. So I use the plants as my guide.

For orchid growers used to things like Cattleya or Phalaenopsis (each new leaf is cause for celebration), many of the plants you can grow in an orchidarium are fast fast fast! Sometimes, when I get a plant such as a small Masdevallia or Pleurothallis in just the right spot in the case, the plant will start firing out new leaves and flower spikes like mad. Well, the orchid version of "like mad", which is not quite tomato plant mad. For example, I have a Masdevallia sernae plant (reputed to be easy to grow) with about 10 leaves that sat like a lump for 6 months, and within a month of getting the right conditions (mostly lighting), shot out many new roots and at least 10 new leaves. This is a bit extreme, but something of the sort is common. Some of the plants flower and grow nearly continuously, with sequentially flowering spikes that pump out flower after flower for a year or flushes of single-flowered spikes coming in every month or two. True, everything is on a small scale, but for sheer cultural abundance and gem like beauty they are incomparable. I particularly like my two Scaphosepalum plants (S. breve and S. aff. swertifolium, which means it is swertifolium or something very similar) - both are sequential bloomers and as one flower passes the next one is already forming, with elaborate curls and protrusions swelling and morphing gradually into the final flower form. The flower buds are just as fun to look at as the open flowers, and the final flower is a three-dimensional fantasy landscape, nearly impossible to photograph.

The Poetry of Dendrobium moniliforme (Choseiran)

Dendrobium moniliforme, called Sekkoku or Choseiran in Japan, is a small caning Dendrobium that has been cultivated for centuries in Japan. Though less well known in the west than its botanical second cousin Vanda (Neofinetia) falcata (Furan or Fuukiran), Dendrobium moniliforme also has an extensive history in Japan of appreciation and selection of botanical varieties. There are various cane heights, cane colors, leaf shapes, leaf colors and variegations, and flower colors. As with Vanda falcata, a few of them are just plain weird, but most of the varieties are lovely little plants.

I have quite a few Vanda falcata but I resisted purchasing Dendrobium moniliforme because they looked kind of ragged and leggy, as caning Dendrobiums are wont to be. A short while ago I purchased a D. moniliforme 'Kosetsu' plant, a fairly typical white flowered variety with plain green leaves and canes, probably not much different from the common wild form other than being on the small side. It was love at first sight. A simple description of my plant or even the photo below fails to convey what enchanted me, but I will try to give you a sense with a prose poetic description (please forgive my amateur attempt).

A stand of ancient trunks densely clustered on a hill, clothed in papery wrapping, shredded and worn, revealing smooth maroon skin. Most are proudly erect, but one kinks a bit as if staggering under the weight of age. In the midst of the ancient ones, two vibrant green youths stand tall, shouting with exuberance, their skin green and tight on their canes and their leaves tender and graceful, unaware that they will soon shed their leaves and join the ranks of the ancient ones. In time, the ancient ones will bear pristine white scented flowers for a few weeks, and then will return to their mute and papered form, each year becoming more shriveled and shredded until they can bear flowers no more. In a month or a year, new youthful canes will push up and exclaim in green that life endures, life persists, life prevails.

That is what my plant says to me. Though I can find very little English literature on the plant, it seems likely to me that similar sentiments are found in Japanese. This is the bonsai of orchids.

Oncidium sotoanum, Orchid of the Month, September 2017

Oncidium sotoanum (known for a long time as O. ornithorhynchum, but recently subject to one of those annoying "precedence" squabbles that seem to be so important to some) is a moderately large plant with a typical Oncidium growth habit: large flattened pseudobulbs, long thin-textured leaves, and seasonally large branching panicles of small flowers. It is reported to grow in northern Central America in humid tropical rain forests at elevations up to 1500 meters. The species is most famous for its strong sweet fragrance, variably described as vanilla, chocolate, or Fruity Pebbles cereal. I would prefer to say that Fruity Pebbles cereal (one of the many triumphs of American marketing, with the goal of making money by damaging the health and aesthetics of world youth - go marketers!) smells like Oncidium sotoanum.

Specimen Oncidium sotoanum plant grown as an ornamental.

Though the Oncidium sotoanum flower is lovely and smells divine, the species is probably better indirectly known for hybrids in which it dominates, including Oncidium Sharry Baby and Oncidium Twinkle. Both of these hybrids have flower panicles and flowers that resemble O. sotoanum except for color, and both are among the most famous hybrids in the orchid grower's world for their scent.

Presumably this famous scent is intended to attract pollinators, probably male Euglossine bees, which are scent collecting bees often associated with orchids. The scent oils in O. sotoanum are produced by specialized flower cells called elaiophores (from ancient Greek "oil bearer") which form the surface of ridges and pillars near the base of the lip, easily visible in the photo below. This part of the lip is a contrasting yellow or orange color, presumably as a cue to bees in locating the oil. The orchid's purpose, as usual, is to attract and then position these bees so that they pick up and drop off pollinia. Unlike many orchids, this one provides something that the bees want (they in turn use the oils to attract female bees, but that is another story).

Single Oncidium sotoanum (with the old species label) flower, showing the yellow-orange callus where scent oils are produced - notice its proximity to the pollinia, which are not visible but are adjacent to the white patch just above the callus. Photo from IOSPE (Jay Pfahl).

This flower along with many others raises an interesting question: why do so many flowers smell good to humans? Not all do of course, witness the famous corpse flower and many similarly scented flowers, intended to attract carrion flies. However, I think it is fair to say that a randomly chosen scented flower will smell pleasant, or at least intriguing, to most humans. Clearly this has nothing directly to do with us - these flowers have evolved to produce a huge variety of volatile compounds to attract pollinators, usually insects, bats, hummingbirds, and the like, but certainly not humans. It is hard to avoid, but also hard to prove, the conclusion that we have evolved to like the scent of flowers and not the other way around. But why? We don't eat them, we don't defend ourselves with them, indeed they seem altogether useless in every way except aesthetically. Perhaps humans evolved to like the scent so that individuals could pick them and elicit sex by presenting them to their amorous choice, much like Euglossine bees? Certainly that is one of their primary uses in current cultures, although rarely stated so baldly. I suppose this is just barely plausible, though it seems a stretch. More likely, flowers act as cues for the eventual location of fruit, a favorite food of a wide variety of monkeys and apes, including us. Hard to test, but fun to think about. Meantime, if you grow orchids, get this species or one of its hybrids - they smell divine.

Pesticides: 100% all natural

Here is a topic that generates a lot of heat and little light. The conventional view among the liberal crowd that I mostly hang out with is that natural is good and man-made is bad. This view is laughably ignorant and sometimes downright dangerous. It is perfectly sound to assess the safety of chemicals, for humans and for other animals and plants, both short term and long term. The ignorance comes with the idea that natural is safe and unnatural is not. In fact, the safety of any product has to be assessed regardless of origin.

If this raises your hackles, let me tell you a story. When I was a kid, one of the home remedy ways to treat my cacti for insects was to exhale cigarette smoke under an inverted jar with the cactus under it, and let it sit for some time (not that I actually did this, but I read about it). Now this is a perfectly sensible method - tobacco smoke contains nicotine, which is a very effective broad spectrum insecticide. Indeed, it is thought that tobaccos (and related plants) make nicotine to kill their insect pests. On a larger scale, nicotine was a major agricultural pesticide from about 1945 through 1980. Nicotine is all natural and totally "organic", but it has a problem - to mammals it is acutely poisonous. The only reason cigarette smokers don't drop dead after a few puffs is because tobacco smoke contains only small amounts of nicotine. Though it was never banned in the U.S., it is no longer in use as a pesticide because of its toxicity.

Here is a (very) partial list of other 100% all natural chemicals that are very hazardous in some way, with their broad class of toxicity and natural source in parentheses: aflatoxin (carcinogen, fungus), ergot alkaloids (neurotoxin, fungus), ricin (cytotoxin, plant), aconitine (neurotoxin, plant), arecholine (neurotoxin, plant), atropine (neurotoxin, plant), scopolamine (neurotoxin, plant), amanitin (cytotoxin, fungus), coniine (neurotoxin, plant), delsoline (neurotoxin, plant), colchicine (cytotoxin, plant), anabasine (neurotoxin, plant), ptaquiloside (carcinogen, plant), ouabain (cardiotoxin, plant), strychnine (neurotoxin, plant), morphine (neurotoxin, plant), and last but not least botulinum toxin (neurotoxin, bacterium), which is the most acutely lethal toxin known (in humans, about 100 nanograms is lethal when injected, a speck of the chemical too small to see by eye). And I am leaving entirely out of the list toxins produced by animals for hunting (snakes, cone snails, and many others) or defense (poison arrow frogs and many others), and irritants (urushiol from poison ivy being the most famous in the U.S.).

All of the above listed chemicals are most likely produced defensively, to prevent contact with or ingestion of the producing organism. They are the product of evolution, which has had notably outstanding success at producing toxins because they are so useful as defensive and offensive weapons. Most of the plant chemicals probably have insects as their main target, because they are the most damaging herbivores. However, in most cases all complex animals share with insects the target of the toxins, so they are often toxic to varying degrees to many or most animals.

This is not to say that man-made chemicals aren't dangerous - everyone is well aware that we have contributed our own ingenious toxins to the huge panoply of natural toxins, sometimes with more enthusiasm than wisdom. In short, each case has to be taken on its own merits (killing intended organisms) and demerits (killing other things). Rather than depending on the idea that natural products are safe, you should assess each chemical by using the amazing amount of information readily available on reputable sources like Wikipedia and government-sponsored toxicity pages.

For the most part, commercially available pesticides (natural or not) are relatively safe because they have been tested for their effects on fish, birds, mammals, etc., though both natural and synthetic pesticides should always be used with care, especially aerosols if they are sprayed. Pesticides allowed for home use are typically safer (it is easy to tell when they are not - if the smallest amount you can buy is huge and costs a bundle, it is NOT licensed for the home). Some are safer than others - again, look it up. You can make your own choice about what you consider acceptable risk for you, your pets, honeybees, fish, or whatever else you care about, but don't fall into the "natural is safe" trap.

Orchidarium 4

The ongoing saga of adapting a commercial Wardian case as an intermediate orchid growing case, my orchidarium.

As you can tell from the photographs in previous posts I tried at first to use natural lighting for my Wardian case. This was not satisfactory because 1) it was very hard to adjust the amount of light, and 2) all the plants oriented leaves and growth toward the window and away from my view.

I am now installing a single LED lamp (Kessil Tuna Sun A160WE, designed for aquarium plants), which will be mounted above the cabinet and will shine through a pane of glass covering a hole I will cut in the steel top. I will probably want to use 2 of these lamps, but I will see how this one works first. The lamp is not cheap, but it has a good spectrum for plant growth but appears natural to the eye (unlike the purple lamps commonly used to grow "recreational" plants), an important consideration if you are going to view your plants rather than smoking them. It is also dimmable so that I can adjust the brightness according the plant response. The lamp has an excellent reputation among aquarists and it is quiet and produces little heat, and none inside the orchidarium (except from the light itself of course). Finally, because the light cone will come from a high point source, I can site plants nearer the center or to the sides (as well as high and low) to meet their specific needs.

As for the earlier vent fan installation, I will be cutting the steel Wardian case top with a Dremel steel cutting wheel and a keyhole hacksaw, which is unpleasant but fairly easy.

Much to my disappointment, lux measurement low in the case from the single A160WE lamp was much lower than I had hoped. I added an A360WE lamp, which together triples the amount of light, and I will be adding reflective material on the back and side walls. I will see how things go. All of my orchidarium plants were intentionally selected to like low light levels (no more than Phalaenopsis light), so I think this will work. Altogether this makes the lighting the most expensive part of the whole project. High intensity fluorescent is still much cheaper, but with the design of my case it would be difficult to mount them outside the case (the entire top is a sheet of steel) and heat would be an issue. The LED lights vent their waste heat outside the case.

Vanilla planifolia, Orchid of the Month, August 2017

The cured and dried seed capsule of the vanilla orchid, whole and chopped

Only a single orchid of the approximately 28,000 known species is widely grown for food - the famous vanilla orchid Vanilla planifolia. More about the food later, for now the plant. The Vanilla genus is one of the earliest diverging branches of the orchid family and their growth habit is unusual, though the flowers are immediately recognizable as orchids, with a lip and a column and all those goodies. Vanilla planifolia (hereafter Vanilla) is described as monopodial (stem and leaves from a single foot), but if you are envisioning a Phalaenopsis or even a Vanda, your image will be way off. Vanilla is a vine. With roots in the earth, the plant can extend tens of meters up a tree trunk to reach higher light in the tree crown. Still, if you shortened and straightened the stem, the plant would look roughly like a wide-leaved Vanda, albeit with a lot of leaves. Members of the Vanilla genus are found across the world in wet tropical climates and Vanilla planifolia is native to Mexico through northern South America, though now also grown commercially in other areas.

Vanilla grown as an ornamental - the trunk is a tree but the leaves are Vanilla

Vanilla (the flavoring) is the seed pod of Vanilla planifolia after curing, the well known dark brown "bean" of the photo at the top. If you google "vanilla" and look at images, they correctly show the beans with a flower, but to my amazement none of them are actually the Vanilla flower, despite the fact that it is quite lovely. On my browser in July 2017, the top hit images in order include a flower of: a Phalaenopsis, a Dendrobium, a flower that is not an orchid at all, another Phalaenopsis (this picture is from an article claiming that vanilla treats just about everything that ails you, including preventing cancer, so I suppose the mismatched flower is the least of its offenses), a Cymbidium, another Dendrobium, another Cymbidium, etc. It is not until the 16th bean/flower photo that there is one that looks like a Vanilla flower. As if this were not enough, a few of the top hit images also include leaves that are definitely not orchid leaves, though I can't say what kind they are. Incredibly, even googling "vanilla flower" gets a top hit that is clearly a Cymbidium flower, though the second and seventh top image hits appear to be Vanilla flowers, which is slightly heartening. As the French say, incroyable! Now these images are found in articles that focus on vanilla as a food (and a dubious medicine), but really: how hard is it to be at least vaguely accurate? It reminds of Hollywood movies and the 45th president of my own United States - truth as marketing or convenience.

An alba form of the actual Vanilla planifolia flower

Rant over, back to reality. The vanilla seed pod arises of course only after pollination of the flower and the flower is very short lasting, so to ensure efficient pod production in vanilla plantations, the plants are hand pollinated. After the pod largely ripens on the vine, the pod is cut and undergoes several steps of curing to develop the best aroma and flavor, largely comprised of the compound vanillin, with a few other compounds contributing to complexity. I am interested in scents and I have a vial of pure vanillin - I don't know about the taste, but I can assure you, you would be hard pressed to tell the scent of vanillin from vanilla bean. And here vanillin is in all its chemical glory, looking as if it might poison you or strip the flesh from your bones, but in fact quite benign and smelling like heaven:

All of the Vanilla species form very large plants, so unless you have a huge greenhouse, a strong desire, or an appropriate outdoor climate, you won't be growing them. But you have eaten them many times, and will many times again. Vive la vanilla!

Paphiopedilum rothschildianum, Orchid of the Month, July 2017

Paphiopedilum rothschildianum flower, which can be 20 to 30 cm across

Paphiopedilum rothschildianum is a commanding plant with an extraordinary flower and is much beloved of Paphiopedilum growers, but it also has other charms that make for a good story. The plant has long glossy strap-like leaves and a tall multi-flowered spike with one of the most distinctive flowers in the plant world. It is terrestrial and grows in Borneo (more about that later) on steep slopes on rocks or among plant detritus that isn't quite soil, usually above running water, often exposed to unusually sunny conditions for an orchid.

Paph. rothschildianum plants in situ in Borneo

If growing only in Borneo isn't enough to make it feel exotic to you, this plant has been found only on the lower slopes of a single mountain in Borneo, Mt. Kinabalu. Okay, it is a really big wide mountain, but still this is one rare plant in nature. There is presumably something special about this location, because this is not a plant struggling to make it by - it is locally abundant. When it has the right conditions it thrives. It could be the microclimate or the soil/rock type is just right, or it could be that its coevolved syrphid fly pollinator is found only in that area. Tropical climates generally support more biological diversity, in part because species are native to a smaller area, but this example is extreme. This gradient of biological diversity is called, cleverly enough, the latitudinal diversity gradient, and it well worth your time to read about - for one thing nobody is sure exactly why it happens.

Speaking of syrphid flies, also known as hoverflies, these are thought to be the pollinators of Paph. rothschildianum. These flies are familiar to those in temperate climate because many species look rather like a bee, with black and yellow stripes (hoverflies don't sting, and their coloration is a case of Batesian mimicry, but the full story takes us too far afield). The larvae of many syrphid flies eat other insects, and mother fly provides for her young by laying eggs among their preferred dinner. In the case of the fly that pollinates Paph. rothschildianum, dinner is aphids and the staminode of the flower has two parts: one part packed with bristles with a fat white tip that apparently looks like a bad aphid infestation to mother fly, and the other part waxy and presumably slippery to the fly. The fly lands to lay eggs (and often does lay eggs, thus dooming her aphid-eating larvae), slips and falls into the bucket-like lip below, and the rest of the process is the same as for all of the Lady Slipper orchids: the slippery walls, the escape route, the pollinia - described many times all over the web. Apparently the trick of luring unwary syrphid flies by mimicking aphids is shared by some other Paphiopedilum and Phragmipedium species, though I am not sure how many. The staminode bristles don't look quite like aphids to me, but then again I don't know what kind of aphid the fly is looking for, and there may be olfactory and tactile cues as well. As for why the rest of the flower is so large and boldly marked, I confess I have only a poor idea. To me it says "beware syrphid fly, here be fake aphids", but perhaps the fly can't figure this out, but is smart enough to learn that huge aphid colonies (appear to) infest these places. This should be an evolutionarily stable strategy if the frequency of real aphid infestations is much higher than Paph. rothschildianum flowers.

Close up of the staminode (the V-shaped structure near the middle), with the white-tipped aphid mimic bristles covering all but the outer (leftward) face, photo from IOSPE.

And finally, another picture showing the strap leaves and the bold flowers as they might appear to a female syrphid fly looking for a great place to lay eggs. Oh yeah, and they look pretty awesome to us humans too.