Accepted name: Dendrochilum unicorne (Ames) L.O.Williams, Philipp. J. Sci. 80: 314 (1952).

Subgenus – Acoridium. Section – Convoluta.




Acoridium unicorne Ames, Orchidaceae 7: 145 (1922).


Origin in the Wild




Elevation in the Wild


2000 metres


Habitat in the Wild


Ramos collected the type specimen on Mount Simakoko and described it as growing on a tree in mossy forest.


The Plants Description


The pseudobulbs either cluster or are spaced 0.5-1.2cm apart on a slightly elongate rhizome. The pseudobulbs are shaped ellipsoid to fusiform. The pseudobulbs measure 0.7-1.5cm long and 0.3-0.7cm in diameter. The pseudobulbs are covered by 4-5 cataphylls while they are growing. The cataphylls soon disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 0.4-2.5cm long. The leaf blades are shaped lanceolate and have acute apices. The leaf blades measure 2.5-7.7cm long and 0.4-1.0cm wide. The leaves are thin textured and have 3-5 distinct nerves; the two outermost nerves are c0.5mm from the leaf margin.


The Inflorescence


The inflorescence is synanthous. The peduncle is erect to somewhat curved and measures 2.6-13.0cm long. The rachis is nodding to (probably?) pendent and measures 1.4-3.0cm long. The flowers alternate distichously and are spaced 1.5-2.0mm apart. There are 2-4 appressed non-floriferous bracts at the base of the rachis. The flowers open from the distal section of the rachis.


The Flowers


Henrik Pedersen wrote that between 8 and 17 flowers grow on an inflorescence (Pedersen 1997). Ramos field notes (specimen NY 39519) state that the flowers are reddish-yellow. The sepals and petals spread widely. The dorsal sepal is shaped oblong and has an obtuse and slightly carinate apex. The dorsal sepal measures 2.4-3.2mm long and 1.2-1.4mm wide. The dorsal sepal is three veined and has an entire margin; the two lateral veins are obscure. The lateral sepals are shaped obliquely ovate and have obtuse to acute slightly carinate apices. The lateral sepals measure 2.4-3.3mm long and 1.6-1.7mm wide. The lateral sepals are three veined and have entire margins; the two lateral veins are obscure. The petals are shaped lanceolate and have obtuse to acute apices. The petals measure 2.2-3.0mm long and 0.7-0.9mm wide. The petals are one veined and have entire margins; there can be two obscure lateral veins. The labellum is porrect and entire. The labellum measures 1.9-2.7mm long and 0.8-1.0mm wide. The labellum is obscurely three veined, has an entire margin and a few scattered ocelli near its apex. The labellum is shaped oblong-pandurate and has a rounded to subacute apex. There is one callus located at the base of the hypochile; the callus is hook shaped. The column is suberect, strongly incurved and measures 1.2-1.4mm long. The column is not hooded at its apex. Stelidia and column foot are absent.


Herbarium Specimens






Specimen 1060 (photo) (syntype)

Specimen 62 (photo) (syntype)





New York Botanical Garden (NY)


Specimen 39519 (photo)




Royal Botanic Gardens, Kew (K)


I could not locate the specimen


National Herbarium Netherlands (L)

Specimen L0058491 (photo)










Other herbarium specimens




I could find no record.


Flowering Season


Flowering plants have been collected in the wild during October.




I do not think this species is in cultivation


Similar Species




Other Information


Ames wrote that there were no close allies of this species. Ames originally described the plant as Acoridium unicorne. L. O. Williams transferred it to Dendrochilum in 1952. L.O. Williams wrote that this species was closely allied to Dendrochilum rhombophorum on account of its habit and morphology. Henrik Pedersen disagreed with this statement (1997) and wrote that this species is isolated within section Convoluta with no close relatives.


There is no definite holotype since Ames worked from 2 herbarium sheets and never recorded from which one. They have both been designated a syntype status.




AMES, Oakes. 1922, Illustrations and studies of the Family Orchidaceae Facsimile 7 Pogonia and its Allies in the North Eastern United States and Other Papers, Ames Botanical Laboratory, North Easton, Massachusetts, Boston.


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


World Checklist of Selected Plant Families. 19 March 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; accessed 19 March 2009.