Dendrobium pugioniforme

A BIT ABOUT . . . Dendrobium pugioniforme

© Gerry Walsh 

   Dendrobium pugioniforme, Dagger Orchid

Dendrobium pugioniforme flower

THE first native orchid I remember seeing in the bush was Dendrobium speciosum. One of the best places at my old child-hood home to see those funny rock lily things was up in the corner of a paddock that backed onto a piece of uncleared bush known as Glennins Bush. Up yonder, there is a big rocky outcrop at the brink of a  small waterfall with a trickle of sweet water showering off the edge – a natural spot to sit down and scoff your lunch and have a cool, cool drink. And yes . . . the three metre wide clump of rock lilies at your feet is now known far and wide as D. speciosum Glennins AM/QOS/AOC.

In September l975 I was squeezing between big boulders and stepping over pools of water to get a closer look at that grand clump. My nostrils were assaulted by an incredibly sweet, almost overpowering aroma. Four inches from the tip of my nose was this funny looking green flower around 2 cms across.  The purple speckles and stripes on its white centre were especially impressive. But the perfume was the thing that grabbed me on that warmer than usual Spring morning.

I wiped my hand through the curtain of pointy green leaves that crowded the rock face. I quickly proved what I later ascertained from a book by W.H. Nicholls, that this funny prickly plant was an orchid with perhaps the most apt name in the orchid world; the Dagger Orchid . . . Dendrobium pugioniforme. The pointy tip to the leaf can pierce human skin as easily as a sewing needle. A couple of little pin prick wounds began to seep blood. But this was quickly ignored as I took another, and another, deep snort from that magical little flower. That perfume was wonderful!

As I crab-walked my way along that ledge I found dozens more flowers. My senses were becoming befuddled by that wonderful, heady perfume. The stinking old rock lilies would have to wait . . .  Such was my first experience with one of the most common species of Australian Dendrobium.  Neglected would be the most suitable adjective I could use to describe the attitude most native orchid growers have for poor old D. pugioniforme.

In September 1995 this was certainly my attitude to it. At that time I was rock hopping up a beautiful rainforest creek down in the Shoalhaven district. I have always been aware that there was lots of D. pugioniforme adorning the trees and small cliffs that channel this leaping little stream on its charge down to the valley floor. And on this particular morning it was all flowering beautifully. 1, of course, was checking out all the plants I could reach without straying too much from my task at hand – it was D. speciosum flowering season you see.

As the hours ticked away I became more and more admiring of D. pugioniforme as a species. So many times over the years I had totally ignored it in my rush to study the more glamorous species. But a chance finding of a truly superb clone of Dagger Orchid made me sit up and re-think this rather stupid attitude. I removed a small piece from this beautiful clone to take home with me. I wrote on the tag: Vivid green and vivid purple. That sums up the special attributes of this plant – a very striking clone indeed and one that most growers would be overjoyed to own a piece of.

Before this clone came to my bush house, there was just a single plant of D. pugioniforme in my collection, an old specimen from my first efforts at growing native orchids. I had often brought back rescued plants from smashed trees and given them to whoever wanted them, mostly non-orchid people like old aunts and next door neighbours. You would have to be horticulturally bankrupt to actually kill them. You just have to water them all the time I would tell them. Even the real hard cases among those recipients still have them alive, I think.

  1. pugioniforme is distributed from Mt Dromedary near Narooma, south coast of NSW, up to the Bunya Bunya Mountains in the north, west of Toowooba. Mt Dromedary, for the buffs of useless trivia amongst us, is the largest free-standing mountain on coastal NSW, as opposed to a mountain that is part of a range. It  was named by Capt. Jim Cook for its similarity to the shape of a camels back.

It rises to 2,600 feet above the ocean, which literally sits at Dromedarys feet. I have never actually been on top of this mountain, despite having spent many a holiday at the nearby hamlet of Bermagui. People who have been up there tell me the view is magnificent and that cool rainforest and big boulders with towering tree-ferns litter the place.

That description just about sums up the kind of environment that D. pugioniforme really goes for. Places like Cambewarra Mountain, Mount Wilson, Mount Warrawalong, Barrington Tops, Comboyne, Dorrigo, Border Ranges, and finally Bunya Bunya. And a thousand places in between. They all share those Mt Dromedary components. And it certainly isn not coincidence that they virtually all have those same, rich volcanic geological origins. D. pugioniforme is not restricted to the red-soil wonderlands of course, but these are certainly the major strongholds.

Anywhere you find a rainforest gully at reasonable altitudes, you could very well run into the Dagger Orchid. But it does not seem to go for the millions of promising gullies that criss-cross the huge sandstone areas between the Hunter River and the Illawarra. Such gullies are often crowded with orchids of many kinds. But unless there is a volcanic connection quite nearby, D. pugioniforme might be absent . . . even if good Myrtle dominated rainforest lines those gullies. This peculiarity becomes less obvious the further northwards one travels.

At the extremes of altitude, up to 1200 metres, D. pugioniforme will still be hanging in there. In the high Antarctic Beech forests, it is usually very abundant where nearly all other species except for D. falcorostrum and Sarcochilus falcatus have chickened out. Cool temperate rainforests dominated by Coachwood are often loaded with D. pugioniforme and S. falcatas, but not much else.

I have been trying to think of another temperate native orchid that so frequently colonises both rocks and trees with the same degree of equalness. I could not state for certain that it is more likely to be found on one or the other. If there is no rockface about, then it will be up the trees. If no suitable trees occur about a rocky outcrop, then it will be found on the rocks. If both are present then D. pugioniforme will be similarly distributed.

  1. pugioniformeis a strictly pendulous species which will grow to around two metres in length without any trouble. If growing on a large boulder, or down the trunk of a large tree, it could tumble over the edge for an indefinite distance, taking a grip with its numerous aerial roots as it cascades. The leaves can be short but broad and plump, like an arrow tip, or very long and wafery thin. These will always have the tell-tale needle point however.

In the wild condition, D. pugioniforme is mostly shy to bloom. This is a logical response to the habitat it prefers to colonise i.e. damp and shady. Sometimes plants can be observed in what amounts to full shade. Yet they still manage to set a few blooms. If given more light they will reply with a greater number of flowers however. Occasional clumps, particularly on rockface, will receive high light levels, and such plants are a sight to behold.

A colony I found some years ago was as large as the side of a house, growing in almost total shade on a small cliff. A few years later, a huge fig tree lost its grip and tumbled off the cliff top, taking all the vegetation that provided the shade. The colony of orchids was left in nearly full sun. The next year that D. pugioniforme flowered like words  could hardly describe. Sure, it had yellowed off a bit and dead patches were streaked through it here and there. But it was trying real hard to doll up the scene with what must surely have been many thousands of highly scented blooms.

These days the vegetation has covered it all up again and the casual observer could never discern the chequered history of that wonderful colony. I have scolded myself frequently for not carrying a camera on that trip. The best specimen plant of D. pugioniforme I have yet seen was benched by Ron Wheeldon of ANOS Wollongong Group at their spring show in about 1988. There was an incredible number of beautiful blooms adorning a large hardwood slab of well established orchid. The specimen had obviously been given the sun treatment with superb results.

As I mentioned, it is easy to grow D. pugioniforme so long as you keep it watered at all times. For a host, you cannot go past a big lump of tree fern fibre. Once established, you will not be able to separate the orchid from this host without killing it. It just loves it!

Most other substrates will be OK but if using old hardwood you must be aware that it will quickly be attacked by that usual boring caterpillar that most slabs are afflicted by from time to time. This is the price paid for keeping your Dagger Orchid wet. Cork is good but it is getting scarce and can be attacked by the same caterpillar occasionally. To sum it up, nearly anything will host this orchid.

Perhaps the best advice I can give to anyone growing D. pugioniforme involves the initial mounting up of the piece. If the plant is a long one, curl the piece up into a series of figure Ss. This is what plant nurserymen refer to as serpentine layering. They use this method on climbing plants and vines. In other words, double and triple up the long wiry stems. If covered in epiphytic moss, lots of little aerial roots will be initiated from the nodes along the stems. New leading growths soon start growing and in a year or two your small piece will romp away. If left hanging as a singular long strand the clumping effect will take many years to achieve.

It is necessary to have at least some roots on the piece of plant you intend to mount up. You may get lucky and successfully establish a long stem without roots but in the main such a piece will quickly die. There are few sights as sickening as a large piece of D. pugioniforme, all nicely mounted up in lush green moss, that later turns  bright yellow because it has no roots to nurture itself. When remounting, you must keep as many of the original roots as possible. In this instance, D. pugioniforme and D.teretifolium are very similar. With most other Dendrobium species, the consequences of root loss are far less life threatening.

The next time you walk through your bush house, take the time to examine your long forgotten Dagger Orchid. Try moving it into a higher light strata – perhaps up near the roof. Feed it up and water it more often. It will surely reward you with an extra flowering effort. And D. pugioniforme, it could be argued, is possibly the most brilliant looking  native orchid, vegetatively speaking, that we have here in NSW. So do not neglect it – its an all-right orchid!