Dendrobium falcorostrum



A BIT ABOUT . . .   Dendrobium falcorostrum


© Gerry Walsh



A great shot of the flowers of D. falcorostrum

A fantastic specimen pot of D. falcorostrum

Another specimen plant of Beech Orchid

MORE PICS AT THE BOTTOM



WOW! I hope I haven’t chomped off more than I can swallow with this bite at Dendrobium falcorostrum. For this is a species that has had more words written about it then the lunatic gun control issue in the USA. I trust that a few more snippets of info on the old Beech Orchid won’t cause mass nausea. Every one has a plant or two of D. falcorostrum in his or her bush house. And everyone probably has their own way of growing it. Indeed, it would appear that D. falcorostrum is nearly everyone’s favourite species.

This was certainly confirmed by the 1988 NSW Epiphytic Orchid Survey (Orchadian Vol. lO No.4) which showed that it is nearly twice as popular as the second placed species, D. speciosum. One quarter of all respondents listedD. falcorostrum as their favourite native species.

Why is this so, I hear you cry out? What is it about D. falcorostrum that places it so high on everyone’s ‘love list’? I suppose the answers are many and varied, none of which are really obvious, but when considered all together, tally up a pretty high score. For a starter, the size of the plant itself is ideal. It isn’t a monstrous lump of a species requiring a couple of itinerant labourers and a removalist truck just to get a specimen plant to a show.

Yet, it certainly can’t be categorised as “one of your botanicals”, an unintelligent phrase that many exotic orchid growers like to toss about with gay abandon when describing any species of Australian native orchid that can’t be used in the cut flower trade.

D. falcorostrum can form a lovely specimen plant in as little as a ten inch pot and yet still lend itself to safe transportation in the average horseless carriage. And once you get it to the show, you can see it from anywhere in the hall without having to squint your eyes like you’ve just hit your finger with a hammer. Being a ‘manageable’ size certainly has its appeal for elderly growers.

An average length ‘cane’, or pseudobulb to be pedantic, of D. falcorostrum would be around 25 to 35 cms. At the upper end of the scale, sometimes canes will reach 50 cms long and 2.5 cms width. At the lower end, flowers can form on dwarfed little runts of maybe 10 cm length if these have grown in sunny spots.

And flowers having such a lovely, crisp white colour certainly inspire admiration from nearly everyone. While other Dendrobiums have white flowers, they don’t always exhibit the tremendous substance that D. falcorostrum flowers do. They are solidly white, not wafery or thin, nor are they spidery flowers. They always look ‘OMO’ white! And the contrasting red striations at the base of the column really stand out, giving a focal point to each bloom.

These wonderful white blooms are attached to racemes up to about 12 cms long that, in the main, are upright or ‘arching erect’, if I can use such off-beat terminology. There are no great air pockets between the flowers; they are spaced closely together, verging on being bunchy, and yet seldom being so. This lends a solid appearance to an already solid looking plant.

But the greatest attribute that D. falcorostrum employs to captivate people has to be its perfume. I know I’m always sprouting off about the perfume of our native orchids. Over the years, I’ve probably nominated a dozen or so species as having the strongest perfume in the Australian bush … many of our orchids are highly perfumed. But I guess I have to override all my other choices for ‘most potent perfume’ and give the title to D. falcorostrum.

There is a simple way to gauge the strength of an orchids perfume. On a warm day at about lunch time, snip a single flower off a plant and place it in a central place inside your home. Shut the place up and go shopping for a few hours. When you unlock the front door you’ll almost certainly be knocked off your feet by the overwhelming fragrance of whatever species you selected. One bloom of D. falcorostrum will pervade every nook and cranny in your house.

One of the most enjoyable experiences I know of is wandering around in forests of Nothofagus moorei . . . common name, Niggerhead or Antarctic Beech. This is not a species with a very wide distribution but, where they do occur, they can be totally dominant. Antarctic Beech is severely restricted to damp and cool highland regions of northern NSW and extreme southern Qld at altitudes exceeding 900 metres.

There about a dozen or so mountainous locations where ‘Beech’ is found in large tracts, but these tracts are rather isolated from each other and there could not possibly be any exchange of genes between them. Beech forests are cool, damp, cool, mossy, cool and dusky. To walk in them is akin to creeping about in a cathedral and trying to avoid waking up you know who. Beech forests are eerie. If you haven’t visited one, you really don’t know what you’ve missed. Get active! They are readily accessible.

The more notable Beech zones are: The Barrington/Gloucester Tops; Mt Banda Banda; Werrikimbe National Park; Dorrigo Plateau; western Dorrigo; New England National Park; western Border Ranges (west of Mt Lindesay); McPherson Tweed Range; Lamington Plateau and Springbrook Plateau. There are other isolated, smaller pockets over the range of these major zones. Beech trees can get real big – not necessarily high – but enormous in girth. They are truly a leftover from ancient times and there are related species found in Tasmania, New Guinea, and South America.

There has apparently been fossil evidence found below the ice caps in Antarctica, thus proving a common link to Gwandala when all these land masses where part of the one set up. The Antarctic Beech is a tree for the ages. It is estimated that many of them are over a thousand years old and aren’t multiplying with staggering success either. D. falcorostrum is reliant for its survival on Nothofagus moorei, for it is totally restricted to this tree as a host.

Very few plants are observed on anything else but, before you all start jumping up and down, odd plants will occasionally be seen on other hosts. In 1982 I found a plant on a giant Coachwood tree that had slipped into the Wilson River near Port Macquarie. This was only about 250 metres above sea level. Nearby, in 1987, I found a plant growing on rocks in amongst big clumps of Sarcochilus aequalis. We thought it to be D. X gracillimum at first because we refused to believe that D. falcorostrum could be found so far out of place. I have seen it on the trunks of Cyathea australis treeferns at Mt Banda Banda in 1980 and at Mt Allyn in 1988 and 2001.

Perhaps the most surprising colony I ever come across was in the southern Barrington Tops in 1992. In an area of about half an acre there were many seedlings and young adults growing very well on mixed species saplings, (certainly not Beech), of no more than arm’s thickness and perhaps fIve metres high. There were big Beech trees nearby that were loaded with D. falcorostrum.

I would guess that the fungus with which this orchid is obviously shackled to for seed germination, and which usually restricts itself to the Beech, has inexplicably colonised those young trees. The Orchid seed cannot tell the difference and has made use of an available niche. It will be interesting to watch the progress of this unusual little patch as the years go by.

Within the confines of the Beech Forest,  D. falcorostrum is often staggeringly abundant. It colonises only the major branches and main trunk of the mature trees. Very rarely would they take root on even moderately thick limbs of say 20 cms. Clumps up to 1.2 metres often sit high up in full sun if the crown of the host tree has died. In some areas dead crowns of Beech trees seem to be fairly common.

The big clumps of D. falcorostrum are highly visible. To see the same big clumps in full bloom in the flowering season is something you will never ever forget. A real big clump can have hundreds of pseudobulbs. Unlike D. speciosum, the Beech Orchid will produce more than one crop of blooms from the leaf axils. They will also flower from any of the nodes along the whole length of the bulb. In this way it is similar to D. gracilicaule although not nearly so freely in this manner.

I have never been able to detect any differences in the flowers or the growth habit of plants from anywhere over the whole distribution of D. falcorostrum. The blooms display remarkably little variation, except the normal and minor variations in flower size within any species. Perhaps the pseudobulb length of Dorrigo plants is a little longer than those from other locations. This is more likely attributable to nutrient availability however.

Plants up on the Border Ranges are a little shorter than most other locations to the south of the northern most population perhaps. These things could never be absolute in any way naturally. So much depends on prevailing rainfall and exposure to the elements. Considering that there is no gene exchange between all the island populations, D. falcorostrum demonstrates an astonishingly stable evolutionary pattern.

Most growers pot their beech orchids in some form of the tried and successful formula of bark and other additives like perlite, pebbles and volcanic rock. Most of these combinations work quite well. Sooner or later the bark will start to go off. Than it will hold too much water and salts etc will build up. New bulbs will become more stunted and you know the rest.

All the while, if you are a poor repotter like me, the top layer of bark will look fairly nice to the eye. Deep down in the pot its another story of course. I am a very lazy grower when it comes to these matters dear reader. Do what I tell you to do and not what I do do. Write that out one hundred times! If you are like me and find excuses for your basic failure than there may be another way.

D. falcorostrum can be successfully mounted. A lot of growers do not realise this. Once again a big lump of treefern will be the best host to mount on. Cyathea or Dicksonia will be suffice. I have had considerable success by just sitting a big lump of treefern on the bench with a beech orchid tied on the top. Cut out a rough niche just wide enough to accept the orchid. Tie it up a bit to keep it upright while the roots find their way into the host. In other words the treefern mount is not hung up. It is simply sat horizontal on the bench. You should keep it moist at all times.

You could also hang this array up if you choose to. Moisture retention is much greater if left sitting on the bench however. Watch out for ferns that will appear from time to time. Pull them out before they take over is my advice. They look attractive but they will be detrimental in the long term. I have kept specimen beech orchids on the same treefern mount for 15 years and all was well. Eventually the whole lot will collapse on you and you will need to start from scratch someday. Regretfully, I have the skeletal remains of plants sitting in rotten pine bark because I did not repot. If you are like me then think about mounting some of the traditionally potted orchids.

For small plants I have used cork as well. I think it is too dry for larger D. falcorostrum plants however. Treefern is so good for mounting beech orchid that I would not bother with anything else. Just remember to use a big hunk of it. D. falcorostrum specimen plants will weigh many kilos when wet. Small mounts will simply tear up. D. falcorostrum will flower well in conditions of shade where other species would not bloom well at all. It could bloom successfully where, Den. speciosum for example, would simply not bloom often at all. The crown of a large Beech tree is often very dense and evolution has allowed D. falcorostrum to handle the dark conditions. Conversely, it will often flower incredibly well in bright sunny conditions.

When your plants start opening their buds it would be handy if you could get down on your knees and pray for cool weather. A flush of hot days can end the flowering performance of your beech orchids from weeks to just a few days. In its own environs up on top of those mountains, at over 900 metres, it rarely gets hot enough in September to damage the blooms. At lower altitude where most of us try to grow it, a high temperature day will cause the blooms to toss it in quickly. Watering often helps but is not successful long term. Just keep on praying folks.

Like any orchid that can grow into very large clumps, it is going to need a heap of tucker or it will not thrive. You must fertilise to get the best results. I chuck a handful of slow release stuff such as Osmacote 9 month formula into all my potted orchids twice a year. Sometimes I will sprinkle light amounts of Blood and Bone onto the bark as well.

I simply have no time in my life to spray water soluble fertiliser around every few weeks. Except on my seedlings and mounted plants. Finally, getting your hands on a plant of D. falcorostrum wont be a problem these days. Various nurseries have seedlings of it and it is commonly seen in the collections of many growers. Treat yourself to a big beautiful Beech Orchid and life will be good to you . . .

Den. falcorostrum in situ

 

D. falcorostrum on Cyathea australis treefern, Barrington Tops, 2001