Accepted name: Dendrochilum trusmadiense J.J.Wood, Lindleyana 5: 93 (1990)

Subgenus – Platyclinis. Section – Eurybrachium.


 
 

Synonyms

 

None

 

Origin in the Wild

 

Sabah

 

Elevation in the Wild

 

1900-2300 metres

 

Habitat in the Wild

 

This species is endemic to Mount Trus Madi in Sabah. Jeffrey Wood wrote that it is found as a twig epiphyte in upper montane ericaceous mossy forest, often on ridges (Wood 2001).

 

The Plants Description

 

The pseudobulbs cluster along creeping rhizomes that measure up to 10cm long. The pseudobulbs are shaped fusiform or cylindrical. The pseudobulbs measure 1.5-3cm long and 0.6-0.8cm in diameter. The pseudobulbs are covered by 3-4 cataphylls while they are growing. The cataphylls soon disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 1-3cm long. The leaf blades are shaped oblong-elliptic to narrowly elliptic and have obtuse apices. The leaf blades measure 9-20cm long and 0.8-2.0cm wide. The leaves have 5-7 distinct nerves.

 

The Inflorescence

 

The peduncle is erect to curved and measures 10-20cm long. The rachis is curved to arching and measures 7-13cm long. The rachis is quadrangular in cross-section. The flowers alternate distichously and are spaced 1.5-2mm apart. There is 1 non-floriferous bract at the base of the rachis. The flowers open from the distal section of the rachis.

 

The Flowers

 

The sepals and petals are pale lemon yellow, the labellum is chocolate brown, and the column is white. The sepals and petals are widely spreading. The dorsal sepal is shaped oblong-elliptic and has an acute apex. The dorsal sepal measures 5.5mm long and 2mm wide. The dorsal sepal has an entire margin and is three veined. The lateral sepals are shaped ovate-elliptic and have acute apices that are slightly carinate. The lateral sepals measure 6mm long and 2.5mm wide. The lateral sepals have entire margins and are three veined. The petals are shaped elliptic and have mucronate apices. The petals measure 5mm long and 2.8-3.0mm wide. The petals have entire margins and are three veined. The labellum is obscurely 3-lobed and concave. The side lobes are rounded. The mid-lobe is shaped ovate and has an obtuse or subacute apex. The margins are incurved, entire and the labellum is three veined. The labellum measures 2mm long and 2mm wide. There are two calli that extend into keels; the keels terminate halfway along the labellum. The column is shaped oblong and measures 0.8mm long. The apical hood is rounded with an entire margin. The stelidia grow from the base of the column, are shaped oblong and have obtuse to somewhat falcate apices. The stelidia measure 0.8mm long and reach the column apex.

 

Herbarium Specimens

 

Holotype

 

Royal Botanic Gardens, Kew (K)

 

Specimen K000078244 (photo)

Specimen K000078245 (drawing)

Specimen K000078242 (photo)

Specimen K000078243 (photo)

Specimen 54100.000

 

 

Isotype

 

National Herbarium Netherlands (L)

 

Specimen L0003778 (photo)

 

UKMS

 

 

Other herbarium specimens

 

Royal Botanic Gardens, Kew (K)

 

Specimen 61494.000

Specimen 60763.000

 

Sabah Parks Herbarium

 

 

Scent

 

Yes, sweetly scented

 

Flowering Season

 

Flowering plants have been collected in the wild during June and October.

 

Culture

 

I do not think this species is in cultivation

 

Similar Species

 

Dendrochilum kamborangense

 

Other Information

 

This plant looks similar to Dendrochilum kamborangense but the two species are in different sections of subgenus Platyclinis. The main differences are Dendrochilum trusmadiense differs because it has a labellum that looks entire and is shaped ovate. There is no column foot.

 

This species is recorded as abundant at 2000 metres on Mount Trus Madi (Wood 2008).

 

The epithet refers to the type locality.

 

Reference

 

WOOD, Jeffrey. 1997, Orchids of Borneo volume 3. The Sabah Society, Kota Kinabalu, Malaysia.

 

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

 

WOOD, Jeffrey. 2008, Two Interesting Species of Dendrochilum, Malesian Orchid Journal Vol 1 (2008).

 

World Checklist of Selected Plant Families. 29 March 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 29 March 2009.