Accepted name: Dendrochilum unicallosum L.O.Williams, Bot. Mus. Leafl. 5: 51 (1937)

Subgenus – Platyclinis. Section – Platyclinis.






Origin in the Wild




Elevation in the Wild


1330 metres.


Habitat in the Wild


This species has been found on Montalban and Mount Irid in Rizal Province. The habitat has been described as mossy forest.


The Plants Description


The pseudobulbs cluster along a short rhizome. The pseudobulbs are shaped fusiform and measure 2.2-4.3cm long and 0.2-0.6cm in diameter. The pseudobulbs are covered by 4-6 cataphylls while they are growing. The cataphylls soon disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 0.9-1.8cm long. The leaf blades are shaped lanceolate and have subacute to obtuse apices. The leaf blades are somewhat narrowed 1/5 to 1/6 from the leaf apices. The leaf blades measure 6.1-10.4cm long and 1.3-2.2cm wide. The leaves are thin textured and have 3-5 distinct nerves.


The Inflorescence


The inflorescence is synanthous. The peduncle is suberect and measures 3.8-11.9cm long. The rachis is probably pendent and measures 7.7-13.8cm long. The flowers alternate distichously, are often slightly flexuose and spaced 1.0-2.0mm apart. There are 3-6 appressed non-floriferous bracts at the base of the rachis. The flowers open from the proximal section of the rachis.


The Flowers


Henrik Pedersen wrote that the flower colour is white (Pedersen 1997). A specimen held at Kew has the following notes “Ovary pale salmon; sepals and petals pale greenish-lemon, sepals flushed pale salmon on the reverse; lip pale greenish lemon; column pale translucent greenish”. The sepals and petals spread somewhat widely. The dorsal sepal is somewhat concave, shaped linear-oblong and has a subacute to abruptly acuminate apex. The dorsal sepal measures 2.8-3.5mm long and 0.8-1.2mm wide. The dorsal sepal is three veined and has an entire margin. The lateral sepals are somewhat concave, shaped elliptic and have acuminate apices. The lateral sepals measure 2.8-3.5mm long and 1.1-1.4mm wide. The lateral sepals are three veined and have entire margins. The petals are somewhat concave, shaped elliptic and have obtuse apices. The petals measure 2.5-3.3mm long and 1.0-1.4mm wide. The petals are three veined and have finely erose to nearly entire margins. The petals are glabrous or have a few scattered trichomes. The labellum is slightly versatile, porrect and 3-lobed. The labellum measures 1.9-2.1mm long and 1.3-1.8mm wide. The labellum is five veined; the two lateral veins are obscure. The margins are entire or finely erose from the base to the side lobes. The side lobes are porrect to gradually recurved, shaped obliquely sub triangular with obtuse to acute apices. The side lobes are distinctly shorter than the mid-lobe. The mid-lobe is shaped sub triangular to oblong and has an obtuse apex. There is a prominent basal callus from which two keels emerge and terminate at the middle of the labellum. The column is erect, slightly incurved and measures 1.2-1.4mm long. The apical hood is prolonged into a rounded finely crenate apex which distinctly exceeds the anther cap. The column foot is short. The stelidia grow upwards from the middle of the column, are slightly incurved and distinctly shorter than the column apex. The stelidia are shaped broadly, sometimes falcately oblong and have rounded apices.


Herbarium Specimens





Specimen 18850 (photo)













Other herbarium specimens



Royal Botanic Gardens, Kew (K)


Specimen 35008




I could find no record.


Flowering Season


Flowering plants have been collected in the wild during September. Plants have flowered in cultivation during the spring.




I have not seen this species, however a specimen is held at Kew that came from the private collection of Richard Warren in the UK.


Similar Species


Dendrochilum ravanii (see this page for the differences)


Other Information


Ames wrote that this species was similar to Dendrochilum longispicatum (now Dendrochilum uncatum var longispicatum) and wrote that the labellum shape was different from all other species known to him. Henrik Pedersen agreed (1997) with L.O. Williams in that he believed there were no close relatives of this species.




PEDERSEN, Henrik. 1997, The Genus Dendrochilum (Orchidaceae) in the Philippines – A Taxonomic Revision. Opera Botanica, Denmark


World Checklist of Selected Plant Families. 27 July 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; accessed 27 July 2009.