Bulbophyllum bracteatum

A  BIT ABOUT . . .  Bulbophyllum bracteatum

© Gerry Walsh

 

 

    

     Bulbophyllum bracteatum, unfortunately, is not well known in cultivation. Once again we have a beautiful orchid that only the small core of species growers appears to bother with. On the other hand, this is quite understandable because  B. bracteatum is seldom encountered in the wild and, to make things more difficult, it has perhaps the narrowest distribution of all the temperate  Bulbophyllums.

 

     The stronghold of  B. bracteatum is the Border Ranges and adjacent areas.   The Richmond Range, Northern Tablelands, Mt. Warning, Lamington Plateau, and the Bunya Mountains circle the distribution neatly. There were old reports of it occurring at Dorrigo, well to the south. I doubted these reports for years but then one day Jim Lykos turned up with a specimen he found on the branches of a fallen Giant Stinging Tree while walking along a tourist trail at Dorrigo. He kindly handed it to me to keep. What a nice guy! Just goes to show you how wrong you can be (about old recordings that is, not Jim).

 

Denis Sinclair of Port Macquarie, a competent observer, reports that he certainly found a single specimen of  B. bracteatum growing in the Mt Boss State Forest, in the Hastings River catchment. This is a good deal south of Dorrigo. Hopefully it exists in higher numbers between the two locales.

 

In September 1987, 1 found myself south of the Queensland town of Warwick, on the mountains that straddle the NSW border. On this day, Ralph Crane and myself located occasional small clumps of  B. bracteatum in the heads of freshly logged Hoop Pines and Tulip Oaks. The orchid appeared to be growing closely in association with  Dendrobium schneiderae. This locale was in a deep, north-facing gully with a large creek flowing through. The tops of the surrounding ridges towered several hundred metres and provided obvious protection. The prevailing breezes could only come from up or down this gully.

 

There were an amazing variety of orchids colonising those logged trees, something like twenty species on perhaps 15 fallen hosts. This was also the spot where I first saw  Sarcochilus weinthalii growing and flowering in the wild. The bush was certainly typical of warm temperate rainforest and all plants were on trees.

 

Another location where I have seen  B. bracteatum growing is very different from the first. This place is a deep gash in the New England Granite Belt where the lowest temperatures must be far colder then either the Border Ranges or the Tweed Range. Snowfalls would not be uncommon on the cliff tops just above where the orchids grow.

 

Altitude would be 900 metres or higher. Yet in the protection of the head of this valley there are comparatively good numbers of  B. bracteatum growing very nicely. In a few spots here, it scrambles over several square metres of rock face – very different to the small clumps at the other locations cited. I have never observed  B. bracteatum growing on the trees here in the granite country. On a collection of mossy boulders balancing on a steep hillside,  B. bracteatum and  B. minutissimum grow fused together in sheets . . . quite unusual indeed.

 

The environmental variance of these locations would indicate that  B. bracteatum is undemanding with regards to its growing requirements, and this is certainly true in the bushhouse. About the only factor I would say that  B. bracteatum would not  tolerate is being wet for two long. For this reason, my preferred host material is virgin cork. Hard treefern works well for a good few years as well but inevitably becomes too wet to the peril of the orchid.

 

I have tried iron bark totems, paperbark logs and hardwood slabs over the years but none of these materials come close to virgin cork as a long-term proposition. The roots love probing deep into the rough fissures of the cork where moisture, coolness and air must be available at just the right ratio. This species likes regular water but must not stay dry, or wet, for long periods. A spray three times a week is far better then a flooding once in a while. Fertilise like every thing else. A little bit often will pay dividends.

 

So long as you pay attention to its simple requirements,  B. bracteatum will cause you no heartaches in cultivation. I consider it very easy to grow. It is not subject to any particular disease, or insect or fungus attack. I do not believe light levels are very relevant either, although more prolific flowering would obviously occur if light were at brighter levels. About the only difficulty intending growers of  B. bracteatum will encounter is obtaining a plant in the first place.

 

If you are able to track down a piece of this uncommon species, you will be a proud owner of one of the prettiest of all the temperate  Bulbophyllums native to Australia.  B. bracteatum plants look for all the world like its very abundant cousin,  B. exiguum. The most notable difference is in bulb size, with  B. bracteatum nearly always 50% or more larger then  B. exiguum, and under perfect conditions, up to triple the size.

 

The other obvious difference is that the bulbs of  B. bracteatum tend to arrange themselves into much more tightly packed clumps, whereas  B. exiguum tends to run in long, spaced-out strands. However, the bulbs are where all resemblance of  B. bracteatum to any  Bulbophyllumsends.

 

The racemes of  B. bracteatum are unique in the orchid family of Australia. There can be up to 25 or so 5mm flowers, creamy with purple blotches, packed closely together along arching racemes up to 10 cms long. But there is also another colour form that is basically blotched brown and very different to the first form mentioned. Each flower is sheathed by a rather obvious, large white/silver bract at its base; hence the specific epithet  bracteatum.

 

Another unusual aspect of  B. bracteatum concerns its seedpod. For a start, the pods are not green, but a silvery cream colour. Shape is another strange trait of the seedpod. Instead of being basically round and ribbed, it is long and thin with a slight banana bend in it.

 

So, if you get the urge to have a plant or two of your own you had better keep your eyes and ears open. Or perhaps you will be one of the lucky ones who puts in the hard work and is rewarded by seeing the very beautiful and very uncommon  B. bracteatum in situ.