Accepted name: Dendrochilum rhombeum J.J.Sm., Blumea 5: 304 (1943)

Subgenus – Platyclinis. Section – Platyclinis.


 
 

Synonyms

 

None

 

Origin in the Wild

 

Sumatra

 

Elevation in the Wild

 

1500 metres

 

Habitat in the Wild

 

This species has been collected in Aceh Province on the forest slope above Penosan, Pucuk Angasan, in the Gayo Highlands.

 

The Plants Description

 

The pseudobulbs cluster together along a short but creeping rhizome. The pseudobulbs are shaped oblong-oval and are narrowed at their apices. The pseudobulbs measure 1.4-2cm long. The leaves are petiolate; the petiole measures 1.5-2cm long. The leaf blades are shaped lanceolate and are narrowed at their obtuse to shortly acute apices. The leaf blades measure 5.75-7cm long and 0.8-1.3cm wide. There are five distinct nerves on the blade.

 

The Inflorescence

 

The inflorescence is synanthous and appears from the pseudobulbs before they have developed. The inflorescence is covered by small black trichomes. The peduncle measures c5.5cm long. The rachis is curved and measures 5.5-6.8cm long. The flowers are spaced 3.5-4mm apart.

 

The Flowers

 

J.J. Smith wrote that between 14 and 16 flowers grow on an inflorescence (Smith 1943). The dorsal sepal is shaped ovate-lanceolate and has an obtuse apex that is minutely apiculate in its centre. The dorsal sepal measures c6mm long and c1.8mm wide. The dorsal sepal is three veined, concave and has an entire margin. The lateral sepals are shaped subobliquely ovate-lanceolate and have acute apices that are minutely apiculate in their centre. The lateral sepals measure 6mm long and 2mm wide. The lateral sepals are three veined and have entire margins. The petals are shaped triangular-lanceolate and narrowed near their acute apices which are shortly apiculate in their centres. The petals have erose margins and are three veined. The petals measure c5.6mm long and c1.75mm wide. The labellum is porrect, clawed basally and 3-lobed. There are three nerves that thicken closer to the labellum apex. The side lobes are wing like, shaped trapezoid and have erose margins. The mid-lobe is shaped rhomboid and has an acute apex. The mid-lobe measures 4mm long and 3.5mm wide. The labellum has a short claw that measures 0.5mm long and 1mm wide. The labellum measures c5.7mm long. The column is slender and arching and measures 3mm long. The apical hood is distinctly prolonged and has a truncate apex with a 5 dentate margin. The stelidia grow from the base of the column and are equal to the column apex.

 

Herbarium Specimens

 

Holotype

 

National Herbarium Netherlands (L)

 

Specimen L0058476

 

Scent

 

I could find no record

 

Flowering Season

 

Flowering plants have been collected in flower during January.

 

Culture

 

There is a photo floating around on the internet, a copy on a well known orchid encyclopaedia, of a plant labelled as Dendrochilum rhombeum, I do not believe this plant is correctly labelled and will not believe so unless an authority on Dendrochilum tells me otherwise. From this photo, I could not see distinct side lobes, a black hairy inflorescence and a claw on the labellum.

 

I do not think this species is in cultivation.

 

Similar Species

 

NA

 

Other Information

 

J.J. Smith wrote (1943) that this species was distinct by the shape of its labellum and the column is similar to Dendrochilum longipes from Borneo. The hairy inflorescence found on this species is not common on Dendrochilum species.

 

Reference

 

COMBER, J.B. Orchids of Sumatra, 2001, Royal Botanic Gardens Kew

 

SMITH, J.J. 1943, Orchidaceae Novae Malayenses, Blumea, Volume 5 number 2

 

World Checklist of Selected Plant Families. 09 January 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 09 January 2009.