Accepted name: Dendrochilum pumilum Rchb.f., Bonplandia (Hannover) 3: 222 (1855)

Subgenus – Acoridium. Section – Convoluta.


 
 
 

Synonyms

 

Coelogyne pumila (Rchb.f.) Rchb.f. in W.G.Walpers, Ann. Bot. Syst. 6: 236 (1862).

Acoridium pumilum (Rchb.f.) Rolfe, Orchid Rev. 12: 220 (1904).

 

Origin in the Wild

 

Luzon and Mindoro

 

Elevation in the Wild

 

1025-2250 metres

 

Habitat in the Wild

 

This species is endemic to Luzon and has been collected in the Lamao Forest Reserve, on Mount Isarog, Mount Banahao, Mount Maquiling and potentially Mount Binuang.

 

On Mindoro this species has been found on Mount Halcon.

 

This plant has been recorded as growing in mossy forest and on exposed ridges.

 

The Plants Description

 

The pseudobulbs cluster on a short rhizome and are shaped fusiform to ellipsoid. The pseudobulbs measure 1.0-6.0cm long and 0.2-0.4cm in diameter. The pseudobulbs are covered by 4-5 cataphylls while they are growing. The cataphylls soon disintegrate into non-persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 0.5-2.6cm long. The leaf blades are shaped linear-lanceolate and have acute to obtuse apices that are sometimes finely mucronate. The leaf blades measure 4.0-11.0cm long and 0.6-1.5cm wide. The leaves have 3-5 distinct nerves; the two outermost nerves are 0.5-1.5mm from the leaf margin.

 

The Inflorescence

 

The inflorescence is synanthous and flowers before the leaf has matured. The peduncle is suberect and measures 1.3-9.5cm long. The rachis is nodding and measures 2-5.5cm long. The flowers alternate distichously and are spaced 3-5mm apart. There are 1-2 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 the flowers number between 7 and 13 on an inflorescence and the flowers are yellow to yellow-green (Pedersen 1997). The sepals and petals spread widely. The dorsal sepal is shaped elliptic-oblong and has an obtuse to rounded apex. The dorsal sepal measures 4.5-6.6mm long and 2.0-2.7mm wide. The dorsal sepal is three veined and has an entire margin. The lateral sepals are shaped oblique, elliptic-oblong to broadly ovate and have obtuse apices that are sometimes minutely mucronate. The lateral sepals measure 3.8-5.8mm long and 2.3-3.0mm wide. The lateral sepals are three veined and have entire margins. The petals are shaped obovate and have obtuse to acute apices. The petals measure 4.0-6.2mm long and 2.7-4.1mm wide. The petals are three veined and have entire margins. The labellum is porrect and 3-lobed. The labellum measures 1.3-1.6mm long and 2.3-3.2mm wide. The labellum is three veined, glabrous and has entire margins. The side lobes are erect, shaped falcately-oblong and have obtuse apices. The side lobes slightly exceed the mid-lobe. The mid-lobe is shaped transversely oblong and has a rounded-truncate apex that is apiculate in its centre. There are three calli, the lateral calli are rounded, minute and located at the base of each side lobe. The median callus is shaped oblongoid and is located at the centre of the hypochile. The column is suberect and measures 0.8-1.2mm long. The column is hooded at its apex. Stelidia and column foot are absent.

 

Herbarium Specimens

 

Holotype

 

W

 

Isotype

 

British Museum of Natural History (BM)

 

Royal Botanic Gardens Kew (K)

 

Specimen K000079144 (photo)

 

W

 

Other herbarium specimens

 

Scent

 

I could find no information

 

Flowering Season

 

Flowering plants have been collected in the wild from October to February.

 

Culture

 

I do not think this species is in cultivation.

 

Similar Species

 

Dendrochilum irigense (see this page for differences)

Dendrochilum exile

Dendrochilum mindorense

Dendrochilum pumilum var recurvum (se this page for the differences)

Dendrochilum schweinfurthianum

Dendrochilum tenuibulbum

Dendrochilum longibulbum

Dendrochilum affine

 

Other Information

 

H.G Reichenbach described this species in 1855 from plant material collected by H. Cumming in the Philippines. Reichenbach changed the name to Coelogyne pumila in 1861. Ames located one of the original specimens, the isotype at the British Museum of Natural History, for his work on Dendrochilum in facsimile 2. The examination of the BM isotype led Ames to conclude that the original description of Reichenbach's was a Dendrochilum, the information Reichenbach gave for the labellum was inadequate.

 

A copy of Henrik Pedersen key to the two Dendrochilum pumilum varieties are as follows:

 

1.    Pseudobulbs clustered on a short rhizome. Rachis 7-13 flowered. Petals 4.0-6.2mm long…………………………………………………………………………………. var pumilum

2.    Pseudobulbs placed up to c2cm apart on a somewhat elongate rhizome. Rachis 11 to many flowered. Petals 3.90-4.1cm long ………………………….. var recurvum

 

The plant depicted as Dendrochilum pumilum in Jim Cootes and David Banks 1995 Orchids Australia article is Dendrochilum tenuibulbum (Pedersen 1997)

 

Reference -

 

AMES, Oakes. 1907, Orchidaceae Halconenses: An Enumeration of the Orchids Collected on and Near Mount Halcon, Mindoro, Chiefly By E.D. Merrill, Bureau of Printing, Manila.

 

AMES, Oakes. 1908, Illustrations and studies of the Family Orchidaceae Facsimile 2, Ames Botanical Laboratory, North Easton, Massachusetts, Boston.

 

AMES, Oakes. 1908, Illustrations and studies of the Family Orchidaceae Facsimile 3, 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. 17 January 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 17 January 2009.