Air, Light & Water

By George Fuller

The essential 5 requirements for all plant growth are air, light, water, nutrition and temperature. Air, light and water are all cheap and easy to provide, the other two being relatively more expensive. We tend to take air, light and water for granted but we need to know their functions as they are very important in the growth of any plant. We cannot take any of the above in isolation as they are all so inter-related and influence each other. There is a need to understand this so that we can provide the right range of conditions from which our plants can achieve the correct balance between all factors.

Grammatophyllum speciosum (tiger orchid) growing in Singapore. Some cropping has taken place. Photo: CheongWeei Gan CC BY-NC 4.0 Deed

Air
Air is a gas that is never still because it is influenced by temperature – any temperature change will either make it move up or down, although we can shunt it along a bit by the use of fans. Air is the agent of evaporation, a critical process for plants that occurs when the air outside the plant is drier than that inside, resulting in air and water being drawn from the plant and released into the atmosphere as vapour.

Air contains oxygen. Whenever a cell divides [ie, the plant is growing], a source of energy must be present in the form of stored carbohydrates – and for the energy in that stored condition to be released there has to be oxygen present. Air enters and leaves the plant via holes in its leaf surface – these holes form 1% of the leaf surface.

Air also contains carbon dioxide. The sun is a great nuclear reactor pelting us with radiant energy which, while we can’t grasp, we can feel as warmth. Green plants, however, can absorb radiant energy from the sun and, by combining it with carbon dioxide from the atmosphere and water that is drawn up through the plant, synthesise a solid form of energy as carbohydrate. As a consquence, the air given off by a plant has a higher ratio of oxygen than that taken in, so they are liberating oxygen of benefit to us. Moving air enhances evaopration which means water is being drawn up through the plant. The more water moving through the plant, the greater the volume of nutrients inducted with it through the roots.

Cypripedium acaule growing in Saskatchewan, northern Canada. Photo: Wikipedia

Light
The sun is our basic source of energy and while we are still trying to work out how to utilise that energy more efficiently, plants have already achieved this. Plants have a unique capacity to accept radiant energy from light and synthesise carbohydrates at a rate relative to the strength of the light.

Plants can have too much light. A sign of this is paling of the leaves to increase reflection of light and thus reduce absorption. If the plant is not able to go pale enough to control absorption then it will burn.* Plants have to have as much light as they can possibly get consistent with the tissues not burning.

The bulk of a plant is water with 3-4% dry matter and a very, very small amount of that is the fertiliser we provide. The bulk of the dry matter is what the plant made for itself by trapping light and mixing it with carbon dioxide and water. There is more to feeding a plant than just feeding it through its roots. Radiant energy is synthesised into sugars, initially in a soluble form which moves through plant sap, then a series of chemical activities takes place which transforms sugars into starches. In that form they are in storage as would be found in pseudobulbs.

The nutrients taken in through the roots are vital to the health of the plant as many of the constituents of chlorophyll, the catalyst for carbohydrate synthesis, are trace elements which are needed in minute quantities but will become toxic in large amounts. If the chlorophyll is not healthy then the plant has no ability to photosynthesise carbohydrates. Therefore, nutrients must be available in the right balance.

Whatever orchid you are growing needs to be subjected to the maximum amount of light that it will tolerate without suffering physical breakdown of tissue because then it will be able to trap the energy required for flower production.

Cymbidium flower spikes are formed over the summer months and whatever happens after then will have no influence on the plant’s ability to initiate flowers. Lush green plants may not flower because they do not have the dry matter content to be induced into flower. There also has to be a differential in day and night termperatures throughout this period to initiate flowering, as most species Cymbidiums [the parents of all our hybrids] come from altitudes where the difference between day and night temperatures is relatively extreme.

Simple diagram of the photosynthesis process. The plant takes in sunlight, carbon dioxide and water; oxygen and carbohydrates are produced. Image: Wikipedia

Water
Water transports nutrients and maintains the turgidity of a plant. A complex system moves fluids up and down a plant which means energy made in the leaves is taken to the roots and storage organs. Trace elements are absorbed in solution through the roots and, to a lesser degree, through the leaves, therefore the more water taken out of a plant through evaporation, the more food solution will be taken in.

An action called osmosis occurs between the inside of the root and the area surrounding it. Between the two is a layer through which nutrients in solution will pass. There needs to be a stronger concentration of soluble salts inside the root to draw the weaker solution from the outside into the plant. The ratio is maintained by evaporation of water from the leaves, leaving the salts behind so the plant can maintain a higher concentration of solution within itself. As long as there is a weaker solution of nutrients surrounding the root, more will be sucked in. However, if you feed a strong solution of nutrients to a plant, the stronger solution will be outside the root and therefore water will be sucked out. The problem is worsened by virtue of the fact that water is also lost by evaporation from the container and potting mix.

Adequate watering is vital. A plant losing water excessively loses its turgidity and the leaves collapse. This is to reduce the area for evaporation to occur. Light and higher temperatures increase evaporation. Water will also influence temperature as, where water evaporates, temperatures will drop. Evaporation cools and direct spraying of water also cools.

If a plant is under stress for a long period due to too high a concentration of solution around the roots, it may be revealed as brown tips to the leaves – brown leaf tips are usually a signal that something is wrong with the roots.

Remember, your plants are talking to you all the time. They are constantly letting you know how comfortable – or uncomfortable – they are, and it is for you to learn their language.

*There are many other reasons, however, why a plant goes pale. There can be too much feed, not enough water or a combination of the two; the roots might be damaged; or it could be starving.

• George Fuller (1929-2015) was involved with the Orchid Council of NZ from its inception in 1975 until his death. At the 1990 World Orchid Conference he was presented with a Gold Medal for his services to orchids. He was curator of Pukekura Park in New Plymouth for 25 years. He was awarded the MBE in 1990 for his services to the community. 

• This article, which has been abridged slightly, is reprinted from Orchids 1998 with the permission of OCNZ.

Happy birthday Jane Goodall

The renowned English primatologist and anthropologist Dame Dr Jane Goodall celebrates her 90th birthday on April 3 – and what a life it’s been.

With the support of renowned anthropologist Louis Leakey, Jane began studying primate behaviour in London in 1958 before going in 1960 (with her mother as chaperone) to Gombe Stream National Park in Tanzania. In1962 Leakey raised funds to send her to Cambridge University to study for her PhD, the university accepting her for a doctorate even though she had no lesser degree at the time (she gained her bachelor’s at Cambridge before her PhD).

Spathoglottis Jane Goodall in the Singapore National Orchid Garden. Photo: Sandra Simpson

The orchid Spathoglottis Jane Goodall was registered by Singapore Botanic Gardens in 2005 with the Royal Horticultural Society. The plant was named in her honour when she visited the National Orchid Garden, part of the botanic gardens, in 2004.

Dame Jane, who will be in New Zealand in June as part of her Reasons for Hope tour, also has a species orchid named for her, Dendrobium goodallianum. Found in Papua New Guinea at about 450m elevation, this large epiphyte has sweetly coconut scented flowers that bloom for only a day. The orchid was discovered for science in 2003 during a collecting trip by members of the Leiden Botanical Garden and Naturalis, and was officially named in 2015 when Dame Jane visited the botanic garden in The Netherlands.

The single plant at Leiden’s Hortus Botanicus grows in a research greenhouse and is not available for public viewing as it is the only known specimen in the world. Unfortunately, no information was gathered during field collection as to how abundant this species was in its original habitat, and since 2003 the region where the orchid was found has succumbed to large-scale logging.

A Cymbidium Mix (more like a recipe)

By Ray Dix

My mix for Cymbidium growing is labour-intensive and based on a ‘no pain, no gain’ theory. It is also a fun thing. All worthwhile activities should have some pain and some fun.

I take a 10-litre paint bucket. I have a garden sieve into which I place 2 scoops of No.3 pinuis radiata bark. I shake the fines out and, as it is good-quality bark, there is very little wood or cambium layer rubbish to remove. With a watering can full of grey water saved from the washing machine (I live in a Third World part of Auckland and all our water comes from the roof into a 5,000-gallon tank so when I am potting in the spring, summer and autumn, clean water is reserved for domestic purposes), I wash the bark to get rid of any remaining fines, to clean it up and also to make it moist.

No3 Kiwi Orchid Bark, made by Bark Products Taranaki, is approximately 8-20mm in size. Photo: Bark Products Taranaki

The sieve of bark is placed on an upturned bucket under any young tree or shrub so that when I wash the bark the water passing through also waters the tree or shrub, most useful in the dry season.

After 2 sieves (about 3 sieves fills the 10-litre bucket) I put in: A handful of oak leaves torn into small pieces; two wine corks chopped into 8 pieces so they are a similar size to the bark, or perhaps a little larger; 2 crushed egg shells; 2 tablespoons dolomite lime; 2 tablespoons of blood and bone; and a quarter teaspoon of trace elements. These are Kiwi measures so are heaped and halfway up the handle as well.

The oak leaves seem a nice organic material to use, having some food value as they break down and, I beleive, a good effect on the pH level of the mix. I like to give a guarantee with any oak leaves taken from my property: “If these oak leaves do not make your orchids grow better, I guarantee that my driveway will be a lot tidier”.

Cym. Hot Port ‘Charity’, perhaps the most famours of Ray Dix’s hybrids, registered in 1996. See more of his 1999 blooms here. Photo: Ray Dix via Casa de las Orquideas website

I enjoy wine so it pleases me to be able to use up the corks, which is a good material to keep the mix open and breaks down only slowly. It is nice to be discriminatory in the use of corks so red-wine corks for red Cymbidiums, white-wine corks for all the other colours, and Champagne corks for your Grand Champions. I do not put corks in the mix for ypung seedlings because I do not believe in under-age drinking and I do not like to see cork pieces on the surface of the mix. Secret drinking is the thing.

Egg shells are a source of calcium. I have a few chooks so it pleases me to use up the egg shells after eating the eggs. Purists will be discriminatory and use egg shells from Rhode Island Reds for red Cymbidiums, those from White Leghorns for whites and so on.

Having placed all these additives into the bark in the bucket, I shake it like mad to mix it all thoroughly, at the same time getting a mini-workout on arm and stomach muscles (saves going to the gym). Then in goes the third sieve and I shake that about too for the final mix, which needs to be a little gentler because now it is a full bucket and I don’t want to spill any over the sides. I put the lid on the moist mix and date it. I have about 6 of these buckets and by using them in rotation, it allows some composting action before use.

• Ray Dix, who died in Auckland on December 8, 2004, aged 71, registered some 22 Cymbidium hybrids of his own breeding, with a particular fondness for the colour red. A founding member of the New Zealand branch of the Cymbidium Society of America (CSA), Ray was its secretary/treasurer for 20 years and was the receipient of many high-level awards for his orchids.
• This article is reprinted with OCNZ permission from Orchids 2000.

A Year of Phalaenopsis

By Fanie Johnson

This checklist, which has been edited slightly, first appeared in Orchids 2008, the Yearbook of OCNZ.

At the end of January or the beginning of February, open your orchid house completely at night for 2-3 weeks, or leave your indoor plants outside in a sheltered spot out of direct sun. This is to cool down the plants sufficiently to induce flowering, giving them time to produce a well-flowered spike lasting into September/October. If you cool them later than this, you may find your plants miss the show season. Reduce watering at this time.

After this cooling period, get your plants warmed up again. You will need to provide more water again and watch the light which tends to get more intense in January and February. The leaves should not get any lighter than a clover-green (if that is any help!) but the plants do need good light to grow strong spikes. If you start losing leaves in summer it may mean that the light is too bright.

Watch for mealy bugs underneath the leaves and in the plant’s crown and spray as necessary. Deal with any infestation now firmly as you will risk damaging the developing spikes and early flowers if you spray later.

April/May your spikes will be evident. Some will need staking already (see the next paragraph). Stay vigilent for mealy bugs, maintain good light and continue watering with your chosen fertiliser added at every watering. Make sure it has all the trace elements but keep it quite weak. Temperatures need to be 26-27C during the day and 17-18C at night.

June/July is the time for staking, which is essential if your flower bloom is to display itself desirably. A stake should be inserted and clipped to the stem before the first buds are fully formed. The spike will naturally want to grow towards the light so, once it is developing, keep the plant in the same orientation. If you move it, do not turn it in another direction or the flowers will point every which-way. As the spike gets taller, add another clip or two up to the bottom bud.

Phalaenopsis philippinensis. Image: Wikipedia

If you intend to buy a new Phalaenopsis, try to buy a plant with an attractive flower in winter or early spring. Enjoy the flower but don’t leave it on the plant for too long – 6 weeks maximum. A phally can retain its flower spike for several months and produce a new, short inflorescence after the first is over, but this sort of treatment weakens the plant for the following year, or even longer. Remove the spike at least before re-potting time.

Avoid showing the plants you have nurtured so lovingly in cold venues for overlong periods. Your plants may not mind 2 or 3 nights in a cold hall, but longer than this may put them into decline or even kill them.

Repot in November using a Cymbidium medium-grade bark [or ponga fibre, Ed]. If your plant is not fully mature (and most store-bought plants are not) then it will need repotting every year until it is about 6 years old. Do not leave your mature plants longer than 2 years without repotting. At re-potting, remove any rotten, overlong or dubious roots with a sterilised cutter. Try not to remove too many roots or, after repotting, you may lose too many leaves. Your main aim now is to go into autumn/winter with as many leaves as possible.

Keep your newly repotted plants as warm as possible – up to 28C daytime and 17-18C at night – through to the end of December. Water regularly but not too often, say every 5-6 days in summer, depending on the weather, including a balanced lquid fertiliser at each watering. The sixth time flush with clean water (do not use city water unless you have to).

Season’s Greetings!

Didn’t we do well?

The Eiffel Tower anchors the Tauranga display at Orchids & More, standing tall and proud in the Mystery Creek Events Centre. Photo: Kelly Lloyd

Tauranga Orchid Society’s display was judged Third in the Large class (9 square metres and over) at the 10th National Orchid Expo at Mystery Creek. Our club would like to thank everyone who contributed towards the display, particularly Maria and Spike who made two towers for us. A smaller one for our own show in May and this larger one for Orchids & More, both of them scale models of the real thing. C’est si bon!

Maria Allen (back to camera) and Glenn Baker (left) work with the Mystery Creek team to assemble the tower. Photo: Sandra Simpson

The Tauranga installation team hard at work arranging plants on September 27, 2023. Photo: Sandra Simpson

Judging took place on Thursday, September 28 and our president, Conrad, came away with Champion Specimen Orchid for his giant Coelogyne cristata alba, which took two people to move on to the display.

Conrad Coenen with his award-winning plant. Photo: Sandra Simpson

Congratulations to all our members who received placings for their plants:
Glenn Baker: Pln. formosana ‘Pukekura Surprise’ 2; Cal. arisanensis 3.
Conrad Coenen: Champion Specimen Plant (a huge Coel. cristata alba); Lyc. Koolena 1, 2 and 3 (for 3 plants); Masd. triangularis 2; Lyc. skinnerei 2; Ddc. wenzelii 2; Den. Santana 3.
Wilma Fitzgibbons: Onc. maculatum 1; Den. Snow Jump 2; Plths. ghiesbreghtiana 3.
Trish Gough: Coel. Unchained Melody 1.
Anna Hansen: Den. speciosum 2; Den. Snowman x delicatum 3.
Diane Hintz: Ascda. Princess Mikasa ‘Sapphire 1; Srts. Janine Banks 1; Onc. splendidum 1 and 2 (2 plants).
John Edwards: Shk. Big Shot ‘Hilo Sparkle’ 2; Epi. Cocktail Hour 3.
Caleb Lamond: Oe. wallissi 1; Den. amethystoglossum 1; Fdk. After Dark 1.
Sandra Simpson: Ddc. glumaceum 1; Paph. Thunder Bay ‘Flash’ x Mendocino ‘Dale’ 2; Cym. Fay Knows 2; Cym. Mary Pinchess 3.
See all the Expo results here and photos of the champion plants here.

Conrad Coenen receives his prize from OCNZ President Glenys MacRae. Photo: Sandra Simpson

Conrad and Sandra, who were both members of the Orchids & More organising committee, said the event was well supported by visitors and all the vendors went home happy. Orchid lovers had come from around New Zealand to attend and, judging by the number of plants and flasks that were sold, they went home happy too!

Orchids & More

Orchids & More at Mystery Creek this weekend is an umbrella event for the 10th National Orchid Expo and, yes, the Tauranga Society is having a (large) display there. The club is also running a bus trip for members on Friday, so if you haven’t yet signed up, hop to it. Details were in the last newsletter.

Why attend? Well, it’s all this good value below for only $10 (under-12 free). Orchids & More is open from 10am-4pm on Friday and Saturday, and 10am-3pm on Sunday at the Mystery Creek Events Centre. Remember that another Orchid Expo won’t roll around for at least 3 years (thanks to Covid, it’s been 4 years since the last one).

Cool having two orchid vendors from overseas, eh? They will both have flasks for sale. And there are plenty of other plants and growing accessories for sale with Kiwi vendors coming from as far as Taupo, Taranaki and Tauranga, and Whangarei.

Gael’s talk is the only Registrant Lecture open to the public.

Companion plants for orchids

Visit an orchid grower and you’ll likely notice a few plants in the orchid house or growing area that could loosely be described as ‘companion plants’. Why are they there? And, if they serve a purpose, what is it?

For some growers regimented lines of neatly potted orchids are a thing of beauty, but for many others the reality is that, like our garden beds, we have a bit of this and a bit of that in amongst our orchids because we like plants. These ‘extras’ need to enjoy the same conditions as the orchids you have, so companion choices need to be made with that in mind.

Some growers prefer to keep the under-bench area as empty and clean as possible to ward off any threats from bacterial and fungal diseases, as well as chewing insects and animals, so you must make up your own mind as to what’s important to you. On the upside, having foliage plants in the growing area provides extra humidity for the orchids – most orchids prefer not to drop below 50% humidity at any time of the year and for levels to be higher in summer.

Plenty of variety in the orchid house in Saigon Zoo and Botanical Gardens, Ho Chi Minh City, Vietnam. Photo: Wikimedia Commons

Ferns are often grown in orchid houses because they can be tucked into darker corners. If they grow under an orchid bench they’re also able to cope with the water they receive as run-off from the orchids above them. Be sure to choose non-invasive varieties like maidenhair ferns. If you grow orchids outside, you’re likely to find ferns rooting into pots thanks to wind and/or bird activity. These ferns need to be removed as soon as possible as they will be varieties like ladder fern or asparagus fern that run rampant, and their rhizomes or roots will quickly take over a pot to the detriment of the orchid.

Bromeliads are often found in orchid collections as easy-care companion plants. Bromeliads, happy with a swish of the hose as the orchids are watered, hold water in their central core or ‘tank’ which helps raise humidity levels in their environs. The leaf colour of bromeliads, which don’t all have spiky leaves, will change depending on the amount of light received.

Streptocarpus ‘A Chorus Line’. Photo: Wikipedia

Streptocarpus are native to Africa and part of the gesneriad family that includes African violets. Enjoying the same humidity as orchids, streptocarpus will grow under a bench quite happily but if you want flowers the plants should receive some decent light each day – and they can flower for months. The more light they have, the smaller the leaves will be.

Begonias, especially the ones grown for their foliage, are another plant often found with orchids, although the Rex varieties will do better inside your home with orchids like Phalaenopsis as they seem to prefer a bit more warmth, especially over winter. Cleopatra begonias are among the foliage types that can be grown in a shade-house. The foliage colours of some types will change depending on the amount of light they receive.

Anthuriums have glossy, heart-shaped leaves and, like a great many orchids, are naturally epiphytes. Grow them in bright, indirect light with good humidity levels. Sound like any other plants you can think of?

Orchids and more in this growing house.

The red-flowered orchid of Vanuatu

By Ron Maunder

June 1977, Vanuatu – After several days a Suzuki trail bike was brought up from a shed for us to overhaul. A pastor had used it until transferred and likely as not the oil had never been changed! Two of us used to ride it up and down to the school where others in our party were staying and to meet the twice weekly plane for mail, etc. I soon decided that I would use the Suzuki on my return trip to Mt Pomare.

Paul, the other rider, set off to Tavio village one Saturday and I sent a message that had been translated into Pidgen to my old guide Daniel asking him to come me the next Saturday. The day finally dawned and I was ready with pack on my back at 6am. The “roads” to the southeastern side of [the island of] Epi were often impassable and Paul told of a rough ride to the end of the road the Saturday previously. Out of the clearing and down the first hill I went. This was better than last time … double concrete strips down the hill to the bottom! On passed vege gardens, a paddock with a couple of horses, and then down the big hill. The concrete strips here only went a few metres and stopped. Nearby stood a concrete mixer and a heap of coral gravel. Obviously, the villagers who volunteered to construct the concrete strips had not come back to complete the job. They would be sorry when the “wet” came! I skidded my way down what remained of the road — two ridges with dry water courses down the middle and either side.

Down on the coast the going was good except for the occasional gate made of lashed branches which had to be opened. The villagers at Moriou were just rousing as I swept
through, sending roosters and hens flying and setting dogs barking. This was great! I didn’t have to explain to everyone where I was going or shake hands with the entire village as on the previous trip!

Then it was some real trail bike work — over rock outcrops, down through streams and up steep banks until the end of the road at Tavio village. I’d come 32km by motorcycle and now I had 5km to go — mostly through thick jungle.

Daniel was ready to leave in 20 minutes or so and away we went with dogs following and soon were out on the black sand of Drummond Bay striding along silently side by side. This time he had no rattley single-barrel shotgun, only his pandanus bag and bush knife and wearing a tattered pair of shorts. There would be no pig hunt this trip and even the dogs seemed to know this and turned back after a mile. Up the cliffs we zigzagged and soon we were heading across the island on the Votlo track. The old huts at the deserted village of Leman were gone — just the graves and overgrown coconut plantation to be seen. Half an hour later we left the track and Daniel headed towards “big fella mountain”.

At one stage we heard cattle bellowing in the distance and Daniel explained “plenty wild cattle”. They even went up on top of Mt Pomare he said and it was obvious cattle numbers were increasing and starting to eat out the undergrowth. We were now starting to climb. The jungle was dark, with terrestrial orchids to be seen occasionally in flower. There were Malaxis, Goodyera, jewel orchids and Habenaria-like varieties. Tree trunks were covered in hoyas, ferns and unusual climbers. I collected several umbrella-like palms but could find no seed. At about 150m above sea level we came to where the Calanthe veratrifolia [syn. Calanthe triplicata] grew. Some stood a metre high with their pyramid-shaped spikes of white flowers, but many had been chewed by cattle. We passed several large banyan trees with their grotesque trunks made up of masses of intertangled roots. At one point we stood beneath a monster casurina tree on a spur and looked down to the coast with its reef and breakers and the volcanic island of Lopevi 15km away, under a dark cloud. Then we were in the land of epiphytes.

Quite suddenly the air was damp, the vegetation changed and there they were, all over the trees. Dendrobiums were in predominance with Bulbophyllums and Cirrhopetalums a close second. There were insignificant Phreatias, Oberonias, Diplocaulobiums and also Coelogynes in great masses. Daniel was soon up the trees or using a long stick to dislodge plants. The ground was a mass of selaginellas and ferns and water was dripping from the moss and filmy ferns on the branches. We had arrived in the cloud-forest region at last. With my pack over half full I decided to leave it and push on to the top with just plastic bags to carry specimens.

We scrambled and clawed our way up the almost vertical slope until we came out on top of the ridge. A faint cow track led around the edge of the volcanic crater and we followed it for 50m or so until we came to an old pipe trig station festooned in moss. The wind was blowing hard and we were in cloud and getting quite cool. Then I saw my red orchids! They were in full flower on almost every tree! Soon I was measuring and comparing different clones and collecting big ones, small-flowered ones, round-petalled ones and ones with indigo-dusted petals.

Daniel climbed up a 5.5m tree to collect clumps of Dendrobium johnsonii with its large white blooms. He also found a compact-bulbed type of Bulbophyllum embedded in the moss and covered in 6-7mm white flowers. Then I saw what looked like our Dendrobium [Winika] cumminghamii. It had branched canes but there were no signs of flowers, buds or pods. It looked as though it might be an orchid so I collected two plants just in case. I gathered my various plastic bags and labelled plants, put them in one big bag and then we headed back down the mountain. I had been to 880m and wondered what the much higher mountains on the island of Esperito Santo would reveal, if I could ever get to them.

Back at the pack I carefully put my orchids inside and left the outside pockets for anything else I came across on my way down. My tennis boots had long since disintegrated and I was now travelling in bare feet, but the soft, damp soil was kind on them. I guess I was dreaming of climbing In New Guinea and collecting orchids when I was brought back to reality by a couple of nasty bites on my ankle. I had got too close to a group of toadstools with its colony of ants which Daniel had disturbed ahead of me. I collected a few small Calanthe plants further on and one or two beautiful jewel orchids. At Leman we stopped and drank coconut water from green nuts that Daniel cut down. Soon I could hear the surf in the distance and it wasn’t long before we were on the beach and heading towards the fires of Tavio.

It had been a long day with few stops and all the time a cracking pace. As soon as invited, I went off to the guest hut and although rats were running about was soon fast asleep. In the morning I woke to the sounds of the pounding surf on the reef and rain beating on the thatch roof. I was anxious to get on the road before the streams became impassable so after thanking Daniel and the elders and paying for my lodgings I set off. I got through some creeks on the bike with my feet held up but in others stalled and had to push it out. As I passed through villages everyone came out to wave and shout. I must have looked a sight! Towel hat, oilskin parka, shorts and jandals with a huge pack on my back and a sack over the handlebars with two 1m palm fronds flapping over my head.

At the big hill I struck my only trouble. Three steams of water were pouring down the track and everything was greasy. With the weight of my pack the bike tipped backwards as I started up the hill and I had to dismount. My jandals were useless and half an hour later I was only 100m or so up the track, when a passerby gave me some help. Eventually I roared into the hospital grounds about 8.30am, covered from head to toe in mud and wet through from perspiration and rain. The next day at 2am the matron was called and took the Toyota to the end of the concrete strips while a woman in labour was carried and hauled up the slippery hill. Needless to say, a lecture was given to all the men on the spot about not completing the concreting!

A botanical study of Dendrobium mohlianum by Bruce Irwin.

Back in the capital Vila I packed up the orchids, selaginellas and filmy ferns I had been asked to collect for Kew Gardens. They cost $26 by airmail and I had to repack them once as I was over the 5kg limit. But what of the plants collected?

A flowering plant of the red Dendrobium was sent to Kew and identified as Den. mohlianum. It had first been recorded in 1862. It is evidently quite variable because a colour plate of an orchid by the same name in Francis P. Hunt’s book The Orchid, scarcely resembles my variety. The plants I collected were grown initially at a minimum of 45degF [7degC] in the quarantine house but for the past 12 months have been growing very well under Novaroof plus 40% shade with open sides covered with 50% shade cloth. There has been no heating during winter, even while frost lay on the ground nearby. They are growing in plastic pots in live sphagnum moss and [in 1981] 400 blooms were counted at the peak of flowering. The flowers are tomato red with an indigo blue lip and an indigo dusting around the petals. The 15-20mm wide flowers come in bunches of up to 5 per node and the nodes of leafless canes flower intermittently for several years. The life of each flower is about 6 weeks. The flower has no scent and the plant can be identified by the orange tips on its new roots. Very occasionally a kiekie will appear at a node, complete with roots and can be removed and grown on. Attempts to hybridize with Den. mohlianum are meeting some success.

The small Bulbophyllum with white flowers was named Bulb. rhomboglossum, while the Den. cunninghamii-Iike plant was identified from a slide I sent of the flowers as Glossorhyncha macdonaldii. This last-mentioned plant has pretty 6-8mm cream flowers with recurved tepals. The perfume Is strong and reminiscent of carnations.

Notes: This is an abridged and slightly amended form of a story that published in three consecutive issues of Orchids in New Zealand, 1981-82 Vol 6, issues 4-6. They may be read here.

Dendrobium mohlianum was first described by German botanist Rudolf Schlechter in 1862 but his valuable orchid herbarium in Berlin was destroyed during World War 2, a loss that is still affecting orchid taxonomy in the 21st century. It is believed that the sample of this plant that Ron Maunder sent to Kew represented its “re-discovery”.

Ron Maunder, who is a Life Member of Tauranga Orchid Society, volunteered at a leprosy hospital in Vanuatu. Read more about him here.