Accepted name: Dendrochilum crassilabium J.J.Wood in J.J.Wood & P.J.Cribb, Check-list Orchids Borneo: 168 (1994)

Subgenus – Platyclinis. Section – Platyclinis.


 
This photo was taken by Malcolm Perry of a plant at the Hortus Botanicus in Leiden and is used with permission.
 
 

Synonyms

 

None

 

Origin in the Wild

 

Kalimantan, Sabah, Sarawak

 

Elevation in the Wild

 

1300-2500 metres

1500 metres within Sarawak

 

Habitat in the Wild

 

Jeffrey Wood described the habitat as mixed hill dipterocarp forest and upper montane forest up to 30 meters high (Wood 2001). This species is also recorded from the Mount Tambuyukon forest on ultramafic substrate. The Kalimantan Isotype was collected in habitat described as "primary ridge forest to 30m high, with little undergrowth, no moss on the bases of the trees. Ridge sloping to steep, sides steep"

 

Specimens have been collected from Kalimantan Timur along the eastern ridge of Mount Sungai Pendan's. In Sabah this species has been collected on Mount Tembuyuken in the Kinabalu National Park. In Sarawak collections have been made in the Limbang District on the route from Ulu Sungai Limbang to Batu Buli and in Marudi District on a trail to Mount Mulu.

 

The Plants Description

 

The pseudobulbs are crowded along the rhizome and shaped ovoid-elliptic or narrowly fusiform. The pseudobulbs measure 1.0-1.6cm long and 0.3-0.4cm 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 0.2-1.5cm long. The blades are shaped narrowly linear-ligulate with acute apices. The leaf blades measure 5.0-10.5cm long and 0.45-0.5cm wide. The leaves are coriaceous and have 3 distinct nerves.

 

The Inflorescence

 

The inflorescence is synanthous. The peduncle is arching to pendent and measures 5.5-12cm long. The rachis is pendent and measures 0.7-1.8cm long. The rachis is quadrangular in cross-section. The flowers alternate distichously and are spaced 3-5mm apart. There are 1-2 non-floriferous bracts at the base of the rachis.

 

The Flowers

 

Jeffrey Wood wrote that between 2 and 6 flowers grow on an inflorescence (Wood 2001). The flowers have dull brownish salmon coloured sepals and petals. The labellum is coloured brownish-salmon, the column brownish olive-green and the anther cap is a cream colour. The dorsal sepal is shaped oblong-elliptic with an obtuse apex. The dorsal sepal measures 7mm long and 2.1mm wide. The dorsal sepal has entire margins and is 3-veined. The lateral sepals are shaped obliquely ovate-elliptic and have acute or obtuse apices. The lateral sepals measure 7.2-7.5mm long and 2.8mm wide. The lateral sepals have entire margins and are 3-veined. The petals are shaped oblong to oblong-elliptic and have obtuse apices. The petals measure 7mm long and 2mm wide. The petals have slightly erose margins and are 3 veined. The labellum is 3-lobed, 3-nerved and measures 7-7.2mm long. The side lobes are lacerate and shaped narrowly triangular with acuminate apices. The mid-lobe is longitudinally concave, spathulate and shaped shallowly retuse or narrowly ovate-elliptic. The mid-lobe is thick and fleshy and the margins are thinner and entire. There are 2 ridges that join at the base of the hypochile to form a U shape. The column is curved and measures 3.0-3.5mm long. The column foot is prominent. The apical hood has a truncate apex that has a 3 or more dentate margin. The stelidia grow upwards from the middle of the column opposite the stigmatic cavity. The stelidia are shaped ligulate or oblong-ligulate, sometimes falcate and have obtuse apices. The stelidia are slightly shorter or slightly exceed the column apex and measure 2mm long.

 

Herbarium Specimens

 

Holotype

 

National Herbarium, Netherlands (L)

 

I could not locate the specimen

 

 

Isotype

 

Royal Botanic Gardens Kew (K)

 

Specimen 60404.000

Specimen K000078894 (photo)

Specimen K000078893 (photo)

 

 

Other herbarium specimens

 

SAR

 

National Herbarium, Netherlands (L)

 

I could not locate the specimen

 

Sabah Parks Herbarium

 

Royal Botanic Gardens Kew (K)

 

Specimen 61447.000

 

Scent

 

I could find no record.

 

Flowering Season

 

Flowering plants have been collected in the wild during March and October

 

Culture

 

I do not think this species is in general cultivation. The National Herbarium in the Netherlands has a specimen in their Hortus Botanicus.

 

Similar Species

 

Dendrochilum pachyphyllum

 

Other Information

 

Jeffrey Wood wrote that this species is similar to Dendrochilum pachyphyllum and has similarly coloured flowers. This species differs from Dendrochilum pachyphyllum because it has coriaceous leaves which are never thick and fleshy. The leaves of Dendrochilum crassilabium are generally longer and the inflorescence is longer than the leaves. The sepals and petals are obtuse. The labellum is longer and the side lobes are lacerate, the mid lobe is thick, retuse and ovate-spathulate.

 

Jeffrey Wood wrote that some of the herbarium specimens showed variation, for example the specimen collected from Mount Tembuyuken has a labellum shaped narrowly ovate-elliptic. Jeffrey Wood wrote that intermediaries between this species and Dendrochilum pachyphyllum may exist.

 

The epithet refers to the thick labellum.

 

Reference -

 

BEAMAN, Teofila, WOOD, Jeffrey, BEAMAN, Reed, BEAMAN, John. 2001, Orchids of Sarawak, Natural History Publications Borneo, Kota Kinabalu, Malaysia.

 

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

 

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