Accepted name: Dendrochilum merrillii (Ames) Pfitzer in H.G.A.Engler (ed.), Pflanzenr., IV, 50 II B 7: 119 (1907).

Subgenus – Platyclinis. Section – Platyclinis.


 
 

Synonyms

 

Acoridium merrillii Ames, Proc. Biol. Soc. Wash. 19: 151 (1906).

 

Origin in the Wild

 

Luzon

 

Elevation in the Wild

 

2100-2545 metres

 

Habitat in the Wild

 

Plants have been collected from Mount Data and Pauai in Benguet Province.

 

The Plants Description

 

The pseudobulbs cluster on a short rhizome. The pseudobulbs are shaped fusiform to ellipsoid. The pseudobulbs measure 1.9-4.0cm long and 0.5-1.0cm 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 1.3-4.4cm long. The leaf blades are shaped lanceolate to narrowly oblanceolate and have acuminate apices. The leaf blades measure 5.3-14.0cm long and 1.4-2.9cm wide. The leaves are thin textured and have 5 distinct nerves.

 

The Inflorescence

 

The inflorescence is synanthous. The peduncle is suberect to curved and measures 8.5-19cm long. The rachis is nodding to probably pendent and measures 6.5-14.0cm long. The flowers alternate distichously and are spaced 2.0-4.5mm apart. There is one appressed non-floriferous bract 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 to yellow (Pedersen 1997). The sepals and petals spread widely. The dorsal sepal is shaped lanceolate to narrowly linear-triangular and has an acuminate apex. The dorsal sepal measures 7.8-9.1mm long and 1.6-2.3mm wide. The dorsal sepal is three veined and has an entire margin. The lateral sepals are shaped somewhat oblique, lanceolate to narrowly linear-triangular and have acuminate apices. The lateral sepals measure 8.0-9.9mm long and 1.9-2.4mm wide. The lateral sepals are three veined and have entire margins. The petals are often somewhat oblique, shaped lanceolate and have acute to acuminate apices. The petals measure 5.9-6.9mm long and 1.4-2.2mm wide. The petals are three veined. The petal margins are quite entire and have somewhat dentate margins at their apices. The labellum is easily versatile, pendent, entire and finely papillose. The labellum measures 4.1-4.6mm long and 2.8-3.3mm wide. The labellum is shaped pandurate and is rounded to slightly retuse at its apex. The labellum is three veined; the veins are sometimes thickened into low keels basally. The margins are entire. The column is suberect, slightly incurved and measures 2.4-2.6mm long. The apical hood is prolonged into a rounded finely crenate apex that distinctly exceeds the anther cap. The column foot is short. There are no stelidia.

 

Herbarium Specimens

 

Holotype

 

Philippine National Herbarium, (PNH)

 

Specimen – destroyed

 

 

Isotype

 

AMES

 

Specimen 38 (photo)

 

Royal Botanic Gardens, Kew (K)

 

I could not locate the specimen

 

Other herbarium specimens

 

 

AMES

 

Specimen 104046 (photo)

 

Scent

 

I could find no record.

 

Flowering Season

 

Flowering plants have been collected in the wild from August to November.

 

Culture

 

I do not think this species is in cultivation.

 

Similar Species

 

Dendrochilum arachnites

 

Other Information

 

Ames wrote that this species has an affinity with Dendrochilum kingii and Dendrochilum exalatum. Dendrochilum merrillii has proven something of a dilemma for taxonomists trying to assign it to a subgenera or section. Dendrochilum merrillii does not have stelidia or an E shaped labellum which are classic characters of Platyclinis and Acoridium respectively.

 

Henrik Pedersen wrote (1997) that the prolonged apical hood on the column is weighted above the absence of stelidia when determining the subgenus Platyclinis and section Platyclinis. Henrik Pedersen stated that this species is more closely related to Dendrochilum arachnites.

 

This species differs from Dendrochilum arachnites by its pandurate labellum and lack of stelidia

 

Reference

 

AMES, Oakes. 1908, Illustrations and studies of the Family Orchidaceae Facsimile 2, 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.