Sarcochilus Falcatus

Each one of us has our favourite native orchid. Of the 58 or so epiphytic species that grow in the NSW bush, 55 of them are among my favorites. Of these, two of them must rank as equal favourites on my overall list. One is Dendrobium speciosum and the other is Sarcochilus falcatus. Common name: The Orange Blossom Orchid.

You wouldn’t have to be a rocket scientist to figure this out after a walk through my bush house, for these two species dominate all the others combined. They are the only two that I make annual pilgrimages into the wilds with the sole purpose of seeing them in bloom. But mostly it’s just for the sheer tonic of being out with them when they are at their best.

Can it be mere coincidence that these two species share almost identical distributions in eastern Australia? They have the widest distributions in their respective genera. That distribution extends from the Mt Windsor Tableland near Cooktown (north Qld) all the way down to extreme north eastern Victoria. In the case of S. falcatus, it only just scrapes over the NSW border into Victoria by less than ten kilometres. And just for the record, D. speciosum only manages to sneak another 40 kms or so south anyway. Over that whole range, they each can be found from sea level to over 1100 metres above the sea.

This huge range of latitude and altitude points to a good deal of variation within these two species. And variability equates, to least, as “interesting”. D. speciosum has at least nine recognised forms and S. falcatus has at least three recognised forms, maybe even more for many of us hard-core observers. Once again, north Qld seems to support a couple of suspicious forms, most notably one that seems to prefer a harsher climate to the mainstream. It often grows on rocks and Casuarinaspecies. It is a small form and doesn’t often have more than three flowers that tend to be quite thin in the segments and claw shaped.

Over the range of S. falcatus there are tremendous differences in flower colour, size, shape, number of flowers and flowering period, as well as at least three distinct perfume types. As I sit here I am trying to think of another species that is so variable. In virtually all the major categories, and apart from D. kingianum and D. tetragonum, I can’t come up with one other that is equally as flexible in form.
S. falcatus can be found in many environments but always there will be a good deal of moisture/humidity in the locale. It is not an orchid that strays far away from the protection of shade and humidity, and high air movement is something that can make or break this species. Rainforest, deep in gullies or high on ridge tops, is its favourite haunt. S. falcatus doesn’t often stray more than a few metres from the rainforest edge.

Rainforest takes many forms of course, and I use that term loosely to indicate any area having ‘brush’ or ‘scrub’ type trees. Such species as Sassafras, Coachwood, Lilly Pilly, Black Wattle, Myrtle, Fig, Cedar, Antarctic Beech, Stinging Tree. The list is nearly endless. These species are often found lining even small gullies and sometimes only a few of them in a clump is enough to induce S. falcatus to move in and set up home sweet home. I have also seen it growing happily on ancient old Monterey Pines, alias to us as Radiata Pine, the most planted introduced pine timber species in Australia.

With a species having the extreme distribution of S. falcatus there are always going to be exceptions to rules. There are some areas, particularly in NSW, where S. falcatus commonly occurs on River Oaks lining creeks and rivers. The best example of this I know of is around the foothills of the Barrington Tops of central NSW. Also, you will have no trouble finding plenty of specimens in the highest Antarctic Beech forests, well over 1000 metres up. And you can find it nearly anywhere in between.

Regions having volcanic origins are particularly attractive to S. falcatus. The great red soil regions such as parts of the lllawarra, Barrington Tops, Comboyne, Dorrigo, etc in NSW, and up to the Sunshine coast Hinterland in Qld are real strongholds forS. falcalus. But you are likely to come across plants on nearly any type of geological foundation – with the exception of sandstone. In this regard I particularly refer to the vast Hawkesbury sandstone regions that surround Sydney.

There is a lot of very suitable territory in the sandstone regions but very little S. falcatus unless you are on one of the volcanic outcrops such as The Mount Wilson Range in the Blue Mts and some of the high peaks in the Wattagans near Wyong. In the Blue Mts there are some spots where large tracts of Coachwood can be found in gullies away from the volcanic outcrops and some of these have good numbers of S. falcatus in them. These are exceptions I stress.

I have never personally observed S. falcatus in the Royal National Park south of Sydney. There is some very likely looking country in ‘The Park’ where you’d nearly bet your house on finding a plant or two. But this area is virtually all sandstone in origin and the lack of a volcanic connection is definitely the reason there is none, or very few plants, to be found. There is a big variation in habitats in the Park, and I would certainly not be surprised to learn it was present – especially around spots that boast some large specimens of Red Cedar. A bit further south there are fairly good numbers of S. falcatus to be seen in the almost identical habitat of the Minnamurra region. The big difference with Minnamurra is the volcanic connection with the Robertson Plateau up above where the Minnamurra River is born.

North of the Hunter River, the big sandstone areas disappear and the occurrence of S. falcatus increases. In the far north of its range, around the Atherton Tableland in north Qld, S. falcatus is confined to the highest peaks of the Great Divide. During a visit in June 1994, I found only small specimens here and there. I was initially disappointed at not finding my favourite species. Finally, at a spot beside a minor arterial road, I was relieved to see some very large clumps in a grove of huge spreading trees – species unknown. Its buds were just starting to split open in June and from a horticultural point of view they were superb forms of S.falcatus, having well filled-in, large and shapely blooms with up to a ten on some of the longer racemes.

I have seen S. falcatus climb down from the trees and walk upright on land … well, I’ve seen it abandon its arboreal lifestyle and colonise rock face at least. This is not a common thing for S. falcatus to do but small colonies of stone dwellers exist in Kangaroo Valley, at Pincher Mountain (near Dungog), Kroombit Tops (near Gladstone) and the Atherton Tableland as mentioned previously. These are examples of small colonies but lone plants occasionally turn up on rock anywhere S. falcatus occurs.

On my way to Ken Russell’s Open Day at Dungog one time, I got my wires crossed and told my dear wife the wrong date – unintentionally of course. I ended up leaving home three days early so spent the extra time out in the bush. In granite country near Tamworth, at an altitude of 1197 metres, and on the western side of the Great Divide in occasional snow fall territory, I decided to pull over for a break. I was stunned to find a single plant of S. falcatus growing in thick moss on a small cliff. It even had a seed pod on it. One hour of searching failed to turn up a single plant of any other epiphytic orchid. Talk about a harsh environment for S. falcatus.

One place where you won’t see S. falcatus grow is on tire outer twigs of host trees, which is exactly where most other Sarcanthinae epiphytes seem to make a bee-line for. I have rarely seen it grow on branches thinner than about garden hose thickness, but even this dimension is rare. There is no doubt that S. falcatus will choose limbs of arm thickness or thicker nearly all the time. It really does prefer the major limbs and the main trunk of its host.

One thing that you can’t avoid doing when bashing out all article on S. falcatus is taking up a lot more space than you would with other less variable species. What can I leave out? Nothing! It has to all go in. So I’m just going to skip through with a few guidelines on what you can expect as normal and what is exceptional, but possible, with this species.

  • Average plants have between four and eight leaves. Exceptional plants can have 20 or more.
  • Average plants are about eight to fourteen cms across. I have seen a single lead plant that was just on 30 cms (a foot) across.
  • Some plants will send out side growths (keiki) with age and form clumps with several leading growths and many smaller ones. I have seen one-plant clumps that would not fit in a bucket.
  • Average flower count per raceme is about five to eight blooms. I have seen up to thirteen flowers on a raceme but if you can grow your plant with ten or more you’re doing really well.
  • Most average size, single lead plants will have two or three racemes. A plant I took to the Adelaide Conference in 1996 displayed thirteen racemes on the single lead.
  • Average flower size is quite variable but up to an inch is fairly typical. I have seen rare plants with 50 mm wide blooms. Some poor forms have stunted blooms of only 12-13 mms.

No discussion on S. falcatus would be complete without mentioning the three main forms of the species. The first is what I refer to as the normal or type form which can be found from near Cooktown to Victoria, and from sea level to over 1100 metres. This is the form that most growers are completely familiar with, and which is found in 99% of the bush houses of Australia. It needs no further introduction.

There is another form that has a much narrower distribution and only occurs at altitudes above 600 metres. That is what growers refer to as the purple-chin form of S. falcatus. A glance at the accompanying photos will reveal this form far more clearly than words. This form frequently has an intense perfume identical to vanilla essence. But the normal form can have the same perfume so this is not 100 per cent reliable.

It has heavily pigmented purple striations on the mid-lobe of the labellum. These striations can appear as solid colouring on some plants, Also, the side lobes are often all intense mustard yellow, far stronger than the light yellow of the normal type form. It should be remembered that this heavy purple striations on the labellum is far more dominating then the little bit of purple colouring that is not uncommon on the normal type form.

This intense purple and mustard combination is absolutely striking, especially for people viewing it for the first time. I used to think that this form was pretty well known by all growers because I frequently ran into it in my travels. But this is not the case and I’m constantly mystified when others express such surprise at seeing it for the first time. The purple chin form is, in my experience at least, only found in NSW, and only from the Barrington Tops north to the Dorrigo Plateau. I have been told it occurs in the Washpool Rainforest just north of Dorrigo. I’ve never been to the Washpool area myself . . . and that’s a situation I won’t tolerate! Sounds like a trip coming up!

That brings us to that other well-known form of S. falcatus that most enthusiasts simply refer to as the ‘big white form’. Once again, a glance at the accompanying photos will explain this form easily, and I won’t grow calluses on my fingertips by flogging this keyboard all night. It is very different to other forms and I am constantly amazed that it hasn’t been given species status as yet. It is so different in nearly every respect.

Flowers on average are much larger and they have their own distinctive colour scheme of basically just white and pale yellow.The only purple present is a faint blush on the keel of the mid-ridge on the reverse of the segments. Its perfume is not even vaguely similar to the type form and can best be described as similar to a fresh cut potato, only much stronger. Plants are very often larger than the type variety and generally have much more sickle, or falcate, shaped leaves.
On mature plants the racemes are often much longer than in the type form. The flowers open up at least a month or six weeks later, despite the fact that it often grows in the same habitat as the type form. I have a photo taken in tire Barrington Tops in November 1993. It shows a big white form plant with just opening blooms, and only 50 cms away from a type form plant just finishing. They are both on the same limb. I am convinced that this is conclusive evidence of the two being different species and not merely forms of the same species. Across the extensive area of this quiet large colony, the type form plants were nearly all finished flowering. But the numerous big whites interspersed among them were only just starting to open up. Yet they all shared identical habitat and environmental conditions. If that doesn’t demonstrate two separate species, probably attracting different pollinators because of their distinct perfumes, then I’m the uncle of a monkey.

The big white form is distributed from Mt Wilson (Hawkesbury River) and the Wattagans (Wyong) north to vicinity of the town of Crows Nest, just north of Toowoomba, Qld. I suspect that it may be found in other districts of southern Qld. Rainforest country at mid altitudes is certainly its preferred habitat. In the Barrington Tops it also grows on the limbs of giant River Oaks, Casuarina cunninghamiana.

Way back in the 1880s, Fitzgerald came up with varietal status for one form of S. falcatus which he published as variety montanus. That handle fell out of favour for some reason or other. For a long time, most growers have been confused over just what form of S. falcatus var. montanus actually represents. Several enthusiasts, including myself, have always thought that it was the big white form. Believe it or not, none of the standard text books of the past 50 years have indicated just what var. montanuslooks like. The main authors, notably Rupp, Dockrill and Jones, were probably as hazy as the rest of us.

In Australian Orchid Research, 1989, Mark Clements was unable to locate an herbarium specimen of var. montanus and so designated Fitzgerald’s painting of it as the lectotype. I don’t own one of the rare volumes of Fitzgerald’s work because they’re worth a trillion dollars. But it clearly shows that var. montanus is actually representative of the purple chin form and not the big white one. His brief description states that var. montanus was known from Mt Wilson and Mt Tomah (Blue Mts} north to Mt Banda Banda and the head of the Bellinger River (Dorrigo). I have great difficulty accepting that the true purple chin form has ever been found in the Blue Mts. The normal type form of S. falcatus occasionally shows some slight purple striation on the labellum chin and I suspect that this is what Fitzgerald was referring to at Mts Wilson and Tomah.

Finally, a word about unusual colour forms of S. falcatus. Over the years, very rare plants have turned up that have a light, shell pink colour where they would normally be white. I doubt this is genetically fixed in most instances because some of these pinks have reverted to white in following years. Perhaps this is the reason why we occasionally hear of someone in Timbuktu finding a pink. But then something always happens to them . . . we never seem to hear about these clones again.

I believe I’ve broken this vanishing act with a specimen I collected up at Kroombit Tops in Sept 1992. I had picked up a hoop pine branch having a large clump of Plectorrhiza tridentata with one small seedling of S. falcatus tangled up in it. I took this home with me and I must confess that I was interested in the Plectorrhiza, not the S. falcatus. So I mounted up the bundle without separating them.

I could scarcely believe it when that little orange blossom orchid flowered for the first time, a month later, as a light pink. And it did so every year until it died some decade later. The only discernible difference with the plant itself is that there is a considerable amount of claret coloured speckling on the underside of each new leaf. This speckling fades away as the leaf matures. I have heard reports of apricot coloured S. falcatus as well but have not seen them myself. Perhaps someone will be gracious enough to fill us all in on this colour.

Because of it being a very common orchid in Australian bush houses, you will hear of more techniques for growing S. falcatus than you’ll hear excuses for not taking on committee positions in orchid societies. I’ve been growing this species for over forty years now and I’ve changed my ideas on its cultivation several times. Some of those changes have been complete about-turns.

The thing that has come out of all this backtracking is that most of the variables I have tested seem to have been successful to some degree. S. falcatus is a fairly hardy orchid and it will withstand a goodly amount of inappropriate treatment. But it should be remembered that it is a Sarcochilus species, and as such, it could decide to toss it in at any stage due to SSDS. This stands for Sudden Sarc Death Syndrome and it’s a condition that very few members of the Sarcanthinae are immune to.

One day it’s alive and well and by the next it’s playing a harp in heaven. Even so – I still think of it as the longest living species within its genus. I reckon I’ve come up with the best possible practices to suit the conditions I have been dealt with regards to my bush house. Your own conditions might be different to mine.
I grow S. falcatus on cork these days. Either virgin Portuguese or that Second-Cut Portuguese. Use a piece around 400 mm long minimum but no wider than about 75mm. Nothing looks as awkward as an S. falcatus plant on a small square mount . . . correction: there is one thing . . . and that’s a S. falcatus imprisoned in a pot. I don’t care whether it grows all right or not – it looks ridiculous and ugly – on a par with Volkswagens painted ‘burnt orange’ or lime green business shirts.

Also very good are Ironbark totems like the ones you buy at the nursery for your indoor plants. These will break down in seven or eight years which is not a bad life span I suppose. I’ve gone off strips of hardwood timber and old fence palings. They eventually rot or get the usual borer in them. But they are cheap and readily available. I have seen S. falcatus grow really well when tied to a sock of plastic ‘Gutterguard’ filled up with coconut fibre. It just doesn’t look natural to my eyes but good results are certainly to be had.

The next thing’ you have to decide is whether to moss or not to moss. I don’t mean sphagnum moss, but I refer to that long green epiphytic moss that grows in damp gullies and ridge tops where you’ll often find S. falcatus growing naturally. This aspect of S. falcatus culture is the one I’ve changed my mind about more times than anything else. I used it extensively and thickly years ago. It certainly aids in the establishment of roots and ensures humidity during long hot summers.

If used too thickly it breaks down and attracts unwanted grubs, springtails and even slaters after a while. A few years ago I decided to go without any moss whatsoever. And still the S. falcatus grew reasonably well, but not to my entire satisfaction. These days I’ve settled for something in between feast and famine. I put just a few strands of this moss behind the oldest leaf and wrap it around the rhizome a couple of times and leave any excess hang. It is not tied on at all.
This frugal application of moss seems to suit my watering and bush house practices pretty well and I recommend it. Young roots will appreciate that little bit of pampering in the very early stages. If you live where you can’t get a supply of this moss (scientific name unknown) I guess you’ll need to try some other sort of moss or a whole different system of cultivation.

Watering is something that I’ve experimented with frequently with S. falcatus. For many years I tried growing them slightly dry with the hope of keeping the dreaded crown rot at bay. Then I learnt that crown rot seemed to effect a percentage of my plants regardless of how I watered. These days I give them what I call an average amount of water and am now of the opinion that it would be difficult to over water this species. Certainly in hot weather I tend to give them more water than most other species. Alternatively, in Winter, hand watering is almost dispensed with because natural rainfall reaches the plants.
S. falcatus will accept a fair amount of shade and still put in a big flowering effort. But I suggest that if you don’t get frosts in your area then you should give them at least 50%. Because I get heaps of frost here in western Sydney, with temperatures down to -4 C occasionally, and lesser minuses being common place, my plants have to live under 70%.

Humidity is important with S. falcatus but it can be hard to provide. My bush house floor is covered with crushed gravel to a depth of 150 mms on average and this never dries out. Because there is 52 tonne of this wet gravel on the ground my humidity level is always satisfactory. On really hot days in Summer I have been known to hang a few of my pet plants up in full shade and only inches above this humid flooring. It must help these plants tolerate the heat and certainly makes me feel better knowing I’ve done all I can to help them. There really isn’t much else I can do short of giving them each a can of beer.

There is no doubt in my mind that S. falcatus likes a good feed of fertiliser – and on a regular basis. Sure, your plants will look OK to you and they’ll flower every year even if you don’t fertilise. But you should be aiming to get the very best out of them.S. falcatus is a species that can look staggeringly more attractive if one plant has longer racemes and bigger flowers then the also-rans beside it at the spring show. With some species it doesn’t seem to matter whether you fertilise or not … they don’t really look any different for all the feeding. But definitely not S. falcatus – it is within your power to make a difference.

Besides SSDS and/or crown rot, which seems to affect the odd plant whatever you do, S. falcatus isn’t particularly pre-disposed to any other specific problem. However, sometimes a plant that’s been growing along great guns for years will suddenly stop growing roots. Gradually the older roots loose their grip and the plant will hang on to the mount with less and less conviction as each root fails, eventually falling to the ground, It doesn’t seem to matter what you do … the condition persists. The plant will still keep flowering all this time.

I don’t know what causes this loss of vigour. I have resurrected the odd worthwhile plant by removing it before it gets too close to the cemetery gates and soaking it in a sugar and hormone solution for a few days. Then I’ve put them in a small pot of loose sphagnum moss, which is then put in a plastic bag for a few weeks. Eventually, some new root may start anew. After a few months it will be ready for planting out again – but this doesn’t always work.

Right at the end of this spoof it has occurred to me that I haven’t said a word about the common name for S. falcatus. Everyone of you would know that its common name is “Orange Blossom Orchid”. And what an apt name this is. The flower colour is that same stylish white as the citrus flowers. As well, the heavy perfume of S. falcatus creates an association with orange trees in bloom, even if it isn’t exactly the same scent.

I suppose I could keep bringing up little snippets about S. falcatus until the cows come home – because, as I said at the beginning, this is species exhibiting great variation over a huge range of latitude and elevation. But I think you must be in the picture by now. So I’ll put away the quill with a final recommendation that you look more closely at this beautiful native orchid. Try a little harder to feed it regularly and if your plants look a bit down on their luck, don’t be afraid of experimenting with them.

As I’ve pointed out . . . S. falcatus is about as user friendly as a Sarcochilus can get. If they aren’t growing the way you’d like them too, then remember – it’s probably your fault.

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