A mystery dendrobe blooms
Some years ago, in my former residence, I cultivated a plant that clearly belongs to Dendrobium section Crumenata aka Rhopalanthe (see Notes below), with elongated pseudobulbs and terete leaves that eventually become slightly flattened. At that time, water supply became a problem and we were forced to use water pumps which generated water of unsatisfactory quality. Many of my plants died in the process which almost entirely wiped out my collection of begonias and Nepenthes. The orchid was one of the casualties. Then two years ago, I was given a plant which at first I thought was Dendrobium polytrichum until the leaves began to flatten like the plant I lost years previously. Last week I noticed two buds developing, and was struck by their sizes, which are evidently quite large in relation to the other plant parts.
Three days ago, the two buds popped open and I at once recognized the flowers as Dendrobium gerlandianum (fide Cootes, 2001). The blooms are about 2.5 cm in diameter from the tips of the sepals and are mildly fragrant. The labellum have purple-red lines and the disc (the surface of the labellum) have yellow-green papillae. Many orchids have such ornamentations to dupe insects into thinking (do insects think, anyway?) that pollen is present.
Would've been the end of story from here, except that the labellum of D. gerlandianum is very different. Attached here is a photo of the sheet containing the drawings from the type. Notice the shape of the labellum, which I have encircled in red for this purpose. On the Latin description it even says "Labellum simplex, brevi-unguiculatum, oblongum, antice brevi-triangulum, obtuse-acutatum..." Translated, it means "Labellum simple, shortly clawed, oblong, in front shortly triangular, obtuse-acute..."
Here is a flattened labellum from one of the flowers, which depicts the presence of side lobes. The identification in Cootes 2001 was clearly mistaken.
As of this writing I do not know the exact identity of this plant at hand. It may even be a new species or a new record for the Philippines. Since retiring from the orchid scene I have had little time and opportunity to update myself from what is going on.
Notes
Most members of Dendrobium sect. Crumenata have since been transferred to the genus Ceraia by Mark Clements in 2003. Ceraia, originally spelled Ceraja, was erected in 1790 by Joao Loureiro; Dendrobium was established by Olof Swartz nine years later. Despite the conservation of the name Dendrobium against Ceraia, I am firm in my belief that Ceraia forms a natural and cohesive group independent from Dendrobium. In 2010 I transferred all the remaining Philippine species overlooked by Clements to Ceraia. However, the notorious and wholesale lumping happening nowadays meant that Ceraia remains an obscure genus. In http://philippineplants.org/Families/OrchidaceaeD-M.html Ceraia has even been merged with Aporum (as a section under Dendrobium), which has very different flowers. Taxonomy these days is being done with eyes wide shut.
Bibliography
Clements M.A. and Jones D.L. 2002. 'Nomenclatural Changes in the Dendrobieae (Orchidaceae) 1: The Australasian Region'. The Orchadian, Vol. 13, Number 11.
-- 2003. 'Molecular phylogenetic systematics in the Dendrobiinae (Orchidaceae), with emphasis on Dendrobium section Pedilonum'. Telopea 10 (1).
Cootes J.E. 2001. The Orchids of the Philippines. Times Editions, Singapore.
Suarez, W. 2010. Notes on Philippine Ceraia, Cylindrolobus and Flickingeria. OrchideenJournal 17:10-15.
Three days ago, the two buds popped open and I at once recognized the flowers as Dendrobium gerlandianum (fide Cootes, 2001). The blooms are about 2.5 cm in diameter from the tips of the sepals and are mildly fragrant. The labellum have purple-red lines and the disc (the surface of the labellum) have yellow-green papillae. Many orchids have such ornamentations to dupe insects into thinking (do insects think, anyway?) that pollen is present.
Would've been the end of story from here, except that the labellum of D. gerlandianum is very different. Attached here is a photo of the sheet containing the drawings from the type. Notice the shape of the labellum, which I have encircled in red for this purpose. On the Latin description it even says "Labellum simplex, brevi-unguiculatum, oblongum, antice brevi-triangulum, obtuse-acutatum..." Translated, it means "Labellum simple, shortly clawed, oblong, in front shortly triangular, obtuse-acute..."
Here is a flattened labellum from one of the flowers, which depicts the presence of side lobes. The identification in Cootes 2001 was clearly mistaken.
Notes
Most members of Dendrobium sect. Crumenata have since been transferred to the genus Ceraia by Mark Clements in 2003. Ceraia, originally spelled Ceraja, was erected in 1790 by Joao Loureiro; Dendrobium was established by Olof Swartz nine years later. Despite the conservation of the name Dendrobium against Ceraia, I am firm in my belief that Ceraia forms a natural and cohesive group independent from Dendrobium. In 2010 I transferred all the remaining Philippine species overlooked by Clements to Ceraia. However, the notorious and wholesale lumping happening nowadays meant that Ceraia remains an obscure genus. In http://philippineplants.org/Families/OrchidaceaeD-M.html Ceraia has even been merged with Aporum (as a section under Dendrobium), which has very different flowers. Taxonomy these days is being done with eyes wide shut.
Bibliography
Clements M.A. and Jones D.L. 2002. 'Nomenclatural Changes in the Dendrobieae (Orchidaceae) 1: The Australasian Region'. The Orchadian, Vol. 13, Number 11.
-- 2003. 'Molecular phylogenetic systematics in the Dendrobiinae (Orchidaceae), with emphasis on Dendrobium section Pedilonum'. Telopea 10 (1).
Cootes J.E. 2001. The Orchids of the Philippines. Times Editions, Singapore.
Suarez, W. 2010. Notes on Philippine Ceraia, Cylindrolobus and Flickingeria. OrchideenJournal 17:10-15.
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