Accepted name: Dendrochilum microscopicum J.J.Sm., Bull. Jard. Bot. Buitenzorg, III, 11: 110 (1931).

Subgenus – Platyclinis. Section – Eurybrachium.


 

Synonyms

 

None

 

Origin in the Wild

 

Kalimantan Timur

 

Elevation in the Wild

 

1500 metres

 

Habitat in the Wild

 

This species is only known from the type specimen. The type was collected on Mount Kemul and the habitat was recorded as lower montane ridge forest.

 

The Plants Description

 

The pseudobulbs clump along a creeping but short rhizome. The pseudobulbs are caespitose, coloured chestnut brown and shaped ovoid and rugulose. The pseudobulbs measure 0.5-0.9cm long and 0.4-0.5cm in diameter. The pseudobulbs are covered by 3 cataphylls while they are growing. The cataphylls disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 1-1.5cm long. The leaf blades are shaped narrowly linear and have shortly acute apices. The leaf blades measure 4.7-7.5cm long and 0.16-0.2cm wide. There are 3 distinct nerves on the blade.

 

The Inflorescence

 

The peduncle is erect and measures 4.3-5.5cm long. The rachis is erect to slightly curved and measures 4.7-5.7cm long. The flowers alternate distichously and are spaced 0.8-1mm apart. There is one non-floriferous bract at the base of the rachis.

 

The Flowers

 

The flower colour is described as yellowish with a brown-red centre. The sepals and petals spread widely. The dorsal sepal is shaped ovate or triangular-ovate and has a shortly acute apex. The dorsal sepal measures 1mm long and 0.75mm wide. The dorsal sepal has an entire margin and is one veined. The lateral sepals are shaped obliquely ovate and have shortly acute apices. The lateral sepals measure 1mm long and 0.75mm wide. The lateral sepals have entire margins and are one veined. The petals are shaped obliquely narrowly-elliptic and have shortly acute apices that are somewhat concave. The petals measure 1mm long and 0.75-0.8mm wide. The petals have entire margins and are one veined. The labellum is entire and concave with its lateral margins incurved. The labellum is shaped reniform and measures 0.5mm long and 0.5mm wide. The labellum is shaped broadly ovate and cupulate with an apiculate apex. The margins on the labellum are entire and there are 3 longitudal nerves on the disc. There are 2 small calli located in the centre of the disc along the lateral nerves. The column measures 0.5mm long and is shaped oblong. The apical hood has a truncate apex. The stelidia grow from the base of the column and do not exceed the column apex. The stelidia are shaped oblong and have obtuse to truncate apices.

 

Herbarium Specimens

 

Holotype

 

BO

 

 

Isotype

 

Royal Botanic Gardens, Kew (K)

 

Specimen K000078884 (photo)

Specimen K000078885 (drawing)

 

National Herbarium Netherlands (L)

 

Specimen L0058675 (photo)

 

 

Other herbarium specimens

 

Royal Botanic Gardens, Kew (K)

 

Specimen 60719.000

 

Scent

 

I could find no record.

 

Flowering Season

 

Flowering plants have been collected in the wild during October.

 

Culture

 

I do not think this species is in cultivation

 

Similar Species

 

NA

 

Other Information

 

At the time when Jeffrey Wood wrote the Dendrochilum of Borneo this species was reputedly the smallest flower of any Bornean orchid. Jeffrey Wood wrote that this species could be pollinated by tiny flies or fungus gnats.

 

Reference

 

WOOD, Jeffrey. Dendrochilum of Borneo, 2001. Natural History Publications (Borneo), Malaysia.

 

World Checklist of Selected Plant Families. 25 February 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 25 February 2009.