Dendrobium cruentum

Selected Species - by Peter Taylor

Dendrobium cruentum

I noted with interest some of the final words of Noel Grundon in his excellent short article on 'Water and Orchids' in the December 2002 edition of Orchids Australia.

Noel writes that "It is difficult to kill an orchid, but it more difficult to grow it well". In general, I would strongly support this statement but, in reference to the Selected Species for this month Dendrobium cruentum, I would contest that it is difficult to grow well and for me at least remarkably easy to kill! However, more on the culture of the species later. First, a little about the photograph accompanying this article. As you can see, it is a well-composed shot of a superb example of the species, perhaps the finest I have seen.

The colour combination of bright scarlet and green is distinct and the photograph is a true reflection of the quality of the flower. But, where did this photo come from and, of course, where is this plant now? The photograph has been widely used in publication of orchid species including the impressive What Orchid is That? edited by Alec Prodgeon. It is generally attributed to Jack Jannese as the slide was in his collection. However, it was taken by Lloyd Bradford, professional photographer and orchid species enthusiast.

I am not sure of the origin of the plant but a division ended up in Jack's collection. He kindly gave me half of his plant. Now, on to the horror story.

On Lloyd's death his collection was sold. It did not contain this special clone. Jack's plant went into terminal decline and efforts to save it failed. My division looked good for about a year then gradually faded in strength and perished. As far as I know the photograph is all that we have of this wonderful clone of Dendrobium cruentum.

A terrific description of the species is to be found in B.S. Williams' The Orchid Growers Manual of 1885 .... "a very distinct and beautiful species belonging to the nigro-hirsute section (of Dendrobium) ... the stems resemble those of Den. jamesianum, the membrane sheathing the internodes being covered with small hairs as in that species. The flowers grow in pairs from the nodes on the ripened leafless stems. The sepals and petals are yellowish-green .... the lip .... is margined distinctly with bright crimson-scarlet, and having the crests and side lacinae of the lip of the same colour".

The species was introduced to English and Continental growers by the firm of Sander and Co. (responsible for the introduction of some of the most desirable species - note how many super species have the specific epithet of Sanderaw, or Sanderianum) in 1884 from "the west coast of the Malayan peninsula". We now know the species to be from lowland areas of Thailand, particularly the humid lowland swamp forest of Ranong province.

The specific name "cruentum" or "blood-red" refers to the striking colour of the lip. Dendrobium cruentum is an endangered species. I have found Dendrobium species closely allied to Dendrobium cruentum, like the equally beautiful D. bellatulum, difficult to cultivate successfully.

Perhaps I do not have sufficient warmth in winter (my general minimum is 12ºC) or maybe my watering regime is the problem. Why is it that some of the most desirable species are so intolerant of less than perfect conditions?

However, all is not lost. About two years ago I purchased, at the Royale Orchids weekend spectacular in June, a promising dendrobium hybrid. I was attracted to the photograph which the vendor had sensibly placed over his tray of seedlings. Its name is Dendrobium Bella Marie 'Hildos', originally from H & R Nursery, Hawaii. The photo showed, to me at least, that the plant was virtually "full" of Dendrobium cruentum - if anything, the flowers while lacking the intense crimson of the "cruentum" lip are of better shape, size and substance.

I grew the seedlings in a mixture of sphagnum and perlite, underpotted and hung up where they got very good winter sun. This year they flowered, true to the bloom in the photograph I had seen. Simply spectacular!

If you can obtain seedlings of this hybrid rush them. You will not be disappointed.

I now grow this hybrid well (as well as the lively Dendrobium Lemon Ice, purchased at the same place and another not to be missed) and now, of course, I am arrogant enough to believe that if I can obtain another "cruentum" I have culture worked out and I will grow it well.

Then, I remember that I thought that I had Dendrobium cuthbertsonii culture licked...!

Peter Taylor

Originally published in "Orchids Australia" August 2003.