Dendrobium spectabile flower visited by the large carpenter bee Xylocopa mordax

Because I live in the tropics, my orchid collection is all outside.  I live in the middle of an state forest which means that insects of all sorts are plentiful (this means the place is also infested with lots of spiders).  It is a common occurrence for orchids to be visited by insects.  However getting a photo of pollinators is not necessarily easy, as most visits are over in seconds.  I was lucky enough to catch this large carpenter bee in flagrante delicto.

The specimen that wasn't

When I go buying orchids I look out for things that are different from what I have in my collection and that are showy and eye catching.    Generally I avoid impulse buying, although I have at times been guilty of buying plants I know nothing about because I am overwhelmed by their beauty.  This is what happened me about a decade ago when I was buying orchids at an orchid show.

The annual orchid show of the Sociedad de Orquidistas de Puerto Rico, is the largest orchid show on the island.  There are plenty of exhibits and many vendors.  In this particular show, one of the vendors had a large plant of Dendrobium spectabile on his table.  The plant had many canes and had several inflorescences.  When I saw it I was in love!  When I asked for the price it turned out the plant was quite expensive.  But that didn’t deter me, I brought it and was very happy with my plant.

The pot and the base of the plant was tightly wrapped with tape, and I surmised that it was so that the potting material would not fall during transport.  But when I arrived at home, I was dismayed to find out that the specimen plant was in fact a bundle of single blooming canes artfully arranged around a small plant that had a single inflorescence.  I was angered and dismayed.  I called the vendor, which was not from the Island, and complained bitterly.  To their credit they said the plant had been sold by mistake by an untrained helper, they offered to refund the money.  That alleviated the monetary loss but I was heartsick about the plant. 

 In my garden things didn’t go well for this orchid, the plant in the center failed to thrive and died relatively quickly for reasons that are not clear.  The single canes rotted and died one by one until only a single one remained.  This cane was large, didn’t have roots, and was leafless.  I gave the cane the kind of tender loving care only an obsessive compulsive orchidist can give to a prized plant and eventually it produced a tiny new cane.  In due course the new cane rooted firmly in the plastic pot where I had planted it.  Then next year it produced a larger cane, and the next year the cane was even larger.  Finally, after several years the orchid bloomed.  I was in ecstasy!

The plant has continued to grow and to bloom faithfully year after year.  Sometimes it blooms twice a year.  I have brought other Den. spectabile plants over the years and all have, for unknown reasons, declined and died.  But the original one continues to thrive, it is indestructible!

To finish this story, I would like to add some advice, if you ever see a plant for sale with many blooming stems, check the bases of the canes.  If they are buried in the media to such a degree that you can’t see the base from where the roots grow, and the media is taped over so that it won’t fall, there is reason to suspect that you are looking at a composite plant made out of two or more plant puts together in a pot.  

Dendrobium Love Knot (Wonder Nishi x spectabile)

Photographed at the 2014 Ponce Orchid society show, Ponce, Puerto Rico.  The genes from the Wonder Nishi parent tried mightly to tame the unruly twisty curlyness of the spectabile parent.  There were not quite successful at the task, but the flower is nevertheless nice.  Given that the essence of the attraction of spectabile is precisely the otherwordly form of its flowers, trying to get a flatter, more conventional form might seem beside the point.

Dendrobium spectabile (Blume) Miq. 1859, an orchid with contorted, otherworldly flowers

The flowers of Dendrobium spectabile have a strange otherworld appareance due to their highly contorted floral parts.  The orientation and twisting of the florarl parts can vary wildly even in the same inflorescences.   The color of the flowers can vary from plant to plant, some are more yellow and some are more purple.  The flowers in the inflorescence can look down, up or sidewise.  In my own plant the flowers, no matter the direction in which their petals are twisted, have their lips pointing downwards, this means that many flowers have sidewise oriented lips.  The texture of the flowers can also vary, my own plant has flowers moderately good substance but some clones that I have seen in exhibitions have flowers which have a leathery texture.

The inflorescences can also vary in the way they show the flowers.  In my plant the flowers are separated by enough space that you can appreciate each one individually.  But some plants I have seen in exhibitions have their flowers all bunched in a ball like inflorescence in which all the flowers are crowded together with their floral parts overlaping each other in an untidy mass.

This plant is well worth growing but it seems individual plants vary in their frequency of blooming.  Some seem to be shy blooming, while others, like my plant, bloom like clockwork each year and sometimes two times in a season.  My only complaint is that the sideshoots my plant has produced have never kept  growing, so after 9 years in my garden my plant still has only a single growing point.

Fragrant Dendrobium, ideal for a perfumed tropical garden



Dendrobium anosmum, all plant of this species I have grown are capable of producing the strong sweet fragrance characteristic of this species, the scientific name, anomum, which means without fragrance, must have been given by an anosmic individual!  This species when well bloomed can produce a powerful fragrance that can be clearly smell from many feet away.

 I have grown Dendrobium orchids for many years and it is one of my favorite orchid genera. Of the Dendrobium, the ones I like best are the fragrant species and hybrids. In the following article I will share details on the species and varieties I have grown, on their fragrances and on the particular quirks that the various species have exhibited under my culture.




Many years ago, in a book whose title I can’t remember, I read about a circular garden that was divided in six parts. Each part of the garden was devoted to a different sense. The garden had five wedges, where all the wedges converged in the center there was another circle, this one devoted to the sixth sense, intuition, and planted with only with golden flowers. This garden captured my imagination, but unfortunately I could not make one. My work as a wildlife biologist has meant that I have lived either in urban areas near universities or deep in protected forests, in these places this type of garden was impossible. But in these settings orchids allowed me to enjoy delightful fragrances, lovely colors and interesting shapes without the need of large spaces, digging, or modifying the landscape in any significant way. Orchids had also the virtue of portability, when I moved, (something that has happened several times during my career), I just took them with me with little problem.


Of all the orchids I have, the Dendrobium represent the best combination of ease of culture, resistance to pests and consistent flowering. This didn’t happen by chance, I did my homework and tried to acquire those species that were best suited for my climatic conditions. Getting the information on the cultural needs of the particular Dendrobium you want to grow is very important as some species need a certain degree of seasonal variation of temperature and moisture to stimulate the buds in the cane to change from the vegetative to flowering mode. Pest resistance is important to me as I don’t want to have to continually use pesticides just to keep my plants in good condition. I do use pesticides but on spot applications and not as preventive measures. In respect to consistent flowering, taking care to give the plants the proper culture they need goes a long way toward achieving regular flowering even on plants that are sometimes labeled as difficult. I suspect that some of the difficulties faced by growers getting their plants to bloom may have to do with growers trying to grow them under conditions that are not really suited to that particular species.

I grow my orchids outside, in a terrace and in a shade house. I live near the central mountain range of Puerto Rico at an altitude of 1000 feet (350 mts), near the center of the Rio Abajo State Forest, where I work. The local temperatures range from 60F (16C) at night at the peak of winter to 90F at daytime in the height of summer, daily temperature variation is about 10 to 15 degrees. There are just two seasons, a dry and a wet one. Humidity fluctuates most of the year between 70 and 80% but varies from 40% during the day at the peak of the dry season to close to 100% at night during the rainy season. The plants are watered weekly during if it doesn’t rain. The plants are regularly watered during the dry season with the exception of those that need a seasonal dry spell. The plants receive fertilizer only when they are growing. Some effort was made to find the optimal sun exposure for each species. It was found that most bloom much better with several hours of exposure to full sunlight in the morning.

Dendrobium anosmum alba, small flowered, small lipped clone

Dendrobium anosmun var. huttoni

The most common type of Den. anosmum is also the most floriferous, it is capable of producing more than sixty flowers on a single cane

Den. anomum variety from Thailand, the flower is suspiciously similar to Den. Nestor but the canes are unique and not similar at all to those of Nestor

Den. Nestor clone, favoring the anosmum parent, but note the fuzzy lip that betrays the parishii ancestry, at time sold as anosmum, all Nestor I have grown have the sweet fragrance associated with anosmum

A Den. Nestor that favors the parishii parent

A Den. Nestor that is quite distinct from most other forms hybrid

A very small lipped form of Den. Nestor with very thick textured flowers

In the front, Den. farmeri var. albiflorum, an outstading clone of this type, in the background a typically colored form. The fragrance is faint but clearly felt when there are many flowers

A flower of Den. farmeri albiflorum

Den. farmeri, a faint fragrance

Dendrobium harveyanum, formerly an extremerly difficult to find species, a slight honey fragrance

Den. crumenatum, powerfully fragrant at certain times of the day

Den. parishii, delightfully frangrant with a sweet note

Den. chrysotoxum, a sweet slight honey fragrance

Den. fimbriatum var. oculatum, a sour citrical fragrance

Den. nobile, a slight sweet fragrance

Dendrobium moschatum it has complex fragrance delightful to some, unpleasant to others

Dendrobium spectabile it has a complex fragrance sweet to some, to others like crushed stinkbugs