Accepted name: Dendrochilum exile Ames, Orchidaceae 2: 84 (1908)

Subgenus – Acoridium. Section – Convoluta.


 
 

Synonyms

Acoridium exile (Ames) Ames, Orchidaceae 7: 80 (1922).

Origin in the Wild

 

Mindoro

 

Elevation in the Wild

 

2,070 metres

 

Habitat in the Wild

 

This species was collected by E.D Merrill on Mount Halcon on Mindoro. The plant was recorded as an epiphyte (Ames 1907).

 

The Plants Description

 

The pseudobulbs cluster on a short rhizome and are shaped fusiform-terete. The pseudobulbs measure 0.7-3.6cm long and 0.1-0.2cm 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 0.7-2.8cm long. The leaf blades are shaped narrowly linear and have acute apices. The leaf blades measure 5.2-12.8cm long and 0.2cm wide. The leaves have 3 distinct nerves on the blade; the 2 outermost nerves are 0.5mm from the leaf margin.

 

The Inflorescence

 

The inflorescence is synanthous and is free from the subtending leaf at the time of flowering. The peduncle is suberect to somewhat curved and measures 2.1-8.2cm long. The rachis is nodding and measures 1.2-3.8cm long. The flowers alternate distichously and are spaced 3mm 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 4 and 13 on an inflorescence and the flowers are greenish-yellow (Pedersen 1997). The sepals and petals spread widely. The dorsal sepal is shaped elliptic and has an obtuse apex. The dorsal sepal measures 3.4-3.9mm long and 1.6-1.8mm wide. The dorsal sepal is three veined and has entire margins. The lateral sepals are shaped slightly oblique, elliptic and have obtuse apices. The lateral sepals measure 3.4-3.5mm long and 1.7-1.9mm wide. The lateral sepals are three veined and have entire margins. The petals are shaped obovate-subspathulate and have obtuse apices. The petals measure 3.1-3.4mm long and 1.4-1.9mm wide. The petals are three veined and have entire margins. The labellum is porrect and 3-lobed. The labellum measures 1.1mm long and 1.9mm wide. The labellum is obscurely three veined, glabrous and has entire margins. The side lobes are erect, shaped falcately-oblong and have obtuse to rounded apices. The side lobes are equal in length to the mid-lobe. The mid-lobe is shaped transversely oblong and has a rounded apex that is apiculate in its centre. There are 3 calli, the lateral calli are minute and located at the base of the side lobes. The median callus is shaped oblongoid and is located at the centre of the hypochile. The column is erect and measures 0.7-0.9mm long. The column is hooded at its apex. Stelidia and column foot are absent

 

Herbarium Specimens

 

Holotype

 

Philippine National Herbarium, (PNH)

 

Specimen - destroyed

 

Isotype

 

AMES

 

Specimen 18870

 

Royal Botanic Gardens Kew (K)

 

I could not find the specimen

 

SING

 

US

 

Scent

 

No

 

Flowering Season

 

The holotype was collected in flower during November.

 

Culture

 

I do not think this species is in cultivation

 

Similar Species

 

Dendrochilum mindorense

Dendrochilum pumilum

Dendrochilum vanoverberghii

Dendrochilum longibulbum

 

Other Information

 

Ames in his facsimile 2 wrote that this species was a link between Dendrochilum tenellum and Dendrochilum tenuifolium. Ames wrote that the shape of the labellum distinguishes it from all other linear leaved species (Ames 1908). Henrik Pedersen wrote (1997) that this species has similar flowers to Dendrochilum mindorense and Dendrochilum pumilum (Pedersen 1997). Pedersen placed this species in section Convoluta on account of the lax inflorescence and flowers that open from the distal section of the rachis. However, this species is the only species in section Convoluta with conduplicate leaves. Because of the conduplicate leaves and the furrowed pseudobulbs it can look like a species from section Acoridium.

 

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.

 

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

 

World Checklist of Selected Plant Families. 01 November 2008. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 01 November 2008.