Dendrobium section Oxyglossum
Jim Cootes’s initial contact with members of Dendrobium section Oxyglossum was many years ago, (probably in the mid 1980s) when he attended a lecture by a world authority on the section, Dr. Tom Reeve. During Dr. Reeve’s lecture he mentioned a species called
Dendrobium pentapterum, which he said was also found in the Philippines. I was immediately interested because this was not a Philippine Dendrobium species with which I was familiar at that time.
After the lecture I approached Dr. Reeve to seek further information about the Philippine member of section
Oxyglossum. Several weeks later Dr. Reeve sent me several photocopies of the type specimen of a Dendrobium
pterocarpum, which was a species I knew from Orchidiana Philippiniana. In a note included in with the photocopies Dr. Reeve informed me that he suspected Dendrobium pentapterum and Dendrobium pterocarpum were one and the same species. At the time I had no reason to doubt Dr. Reeve’s identifications.
Subsequently Dr. Reeve published a revision of the section in 1989 in
Notes from the Royal Botanic Garden Edinburgh entitled A Revision of Dendrobium section Oxyglossum (Orchidaceae).
The vast majority of the species, and there are about 30 members of this section, are found in the high mountains of New Guinea, with a few species in the islands of the Pacific Ocean, and also in Sulawesi.
There are several reasons why the members of Dendrobium section Oxyglossum are popular with orchid growers world-wide. Firstly, the colors are brilliant and in some species the blooms almost glow; the plants are considered to be miniature growers; and thirdly the flowers are very long lasting. Sadly, for people living in tropical climates these are not plants for you, as they will not grow in the heat of the lowlands.
About 18 months back, the first author was sent a selection of pictures of a Dendrobium species, which had been found in the mountains of the province of Davao, on the island of Mindanao. It was immediately recognized as a member of the Dendrobium section Oxyglossum. What was a little confusing, at first, was the coloration of the blooms, which in this plant were a pale pastel pink, with a slightly darker pink labellum.
I went back to my files and found the photocopy of the herbarium specimen of Dendrobium pterocarpum, and the pictures matched the drawing on the herbarium specimen very closely, apart from the coloration of the blooms. This colour difference was of no major concern though, I hasten to add. One only has to examine a series of images of different cultivars of any widespread orchid species to see there is considerable color differences between individual plants. Just look at the many different colour forms of Dendrobium anosmum, Euanthe sanderiana, Dendrobium victoriae-reginae, just to mention a few examples. Dendrobium pterocarpum is endemic to the high mountains of northern and eastern Mindanao, where it grows as an epiphyte among mosses, at elevations over 1,000 meters.
Several months later the first author was again sent pictures of another species of Dendrobium from section Oxyglossum. This plant was a true miniature, barely 4 centimeters tall. The plant proved to be the very widely distributed
Dendrobium masarangense, which is known from Sulawesi (from where the first plants were described), New Guinea, New Britain, the Solomon Islands, Bougainville, Vanuatu, New Caledonia and Fiji. In the Philippines, it has been found at high elevations in northern Mindanao, where it is almost hidden by the mosses in which it grows.
These “hidden treasures” are further proof that countless botanical surprises are out there in the forests, or spread around islands and nations, where one does not immediately expect it to find them. Only the tireless efforts of taxonomists in the early days, and explorers, orchid growers and collectors nowadays, sharing information and pictures, which bring to light a better understanding of what must be conserved for future generations.