Accepted name: Dendrochilum crassifolium Ames, Orchidaceae 6: 49 (1920)

Subgenus – Platyclinis. Section – Platyclinis.


 
 
 

Synonyms

 

None

 

Origin in the Wild

 

Sabah and Sarawak

 

Elevation in the Wild

 

1300-2400 metres

(1700-1800 metres within Sarawak)

 

Habitat in the Wild

 

Within Sarawak plants have been collected on Mount Murud and along the route from Ba Kelalan to Mount Murud (Camp 3).

 

In Sabah this plant has been collected on Mount Kinabalu, Mount Alab, the Keningau to Kimanis road and in Sipitang District at the Rurun River headwaters.

 

Jeffrey Wood described the habitat as “lower montane forest; low, rather open, wet, somewhat podsolic forest, with a very dense undergrowth of Pandanus spp. And rattans; cleared, steeply sloping roadsides on sandstone and shale outcrops partially covered with grass and small bushes, in full sun.” (Wood 2001).

 

This plant is an epiphyte and occasional terrestrial.

 

The Plants Description

 

The pseudobulbs cluster together on a short rhizome; the pseudobulbs are spaced 0.5cm apart. The pseudobulbs are shaped ovoid, ovoid-elliptic or conical and measure 0.8-3.5cm long and 0.5-1.2cm in diameter. The pseudobulbs are yellowish. The pseudobulbs are covered by 3-4 cataphylls while they are growing. The cataphylls disintegrate into fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 2.0-6.0cm long. The leaf blades are shaped linear to linear-ligulate or oblong to oblong-elliptic and have obtuse to shortly acute, or subacute and mucronate apices. The leaf blades measure 3.0-18.5cm long and 0.6-3.8cm wide. The leaf blades are either rigidly or toughly coriaceous or thick and fleshy and have 5-7 distinct nerves along their length.

 

The Inflorescence

 

The inflorescence is synanthous and appears from the pseudobulbs while they are very young or when they have nearly fully expanded. The peduncle is erect to gently curved and measures 12-18cm long. The rachis is pendent and measures 16-36cm long. The rachis is quadrangular in cross-section. The flowers alternate distichously, are spaced 3.0-5.0mm apart and up to 1cm in the proximal section of the rachis. There are no non floriferous bracts at the base of the rachis.

 

The Flowers

 

The sepals and petals are green, greenish cream, greenish yellow or pale yellow with a darker green nerve on their exteriors.  The labellum is green between the side lobes and has 2 steaks from the middle of the side lobes to the middle of the mid-lobe. The 2 streaks are either dark green, pale yellowish brown or orange. The column is pale yellow and the stelidia are a white shade. The sepals and petals are either with or without minute trichomes at their base. The dorsal sepal is shaped oblong-elliptic to narrowly elliptic and has an acute to shortly acuminate apex. The dorsal sepal is 3-veined and has entire margins. The dorsal sepal measures 6.0-7.0mm long and 1.7-2.5mm wide. The lateral sepals are shaped oblong-elliptic and have acute to shortly acuminate apices. The lateral sepals measure 5.8-7.0mm long and 1.5-2.5mm wide. The lateral sepals are 3-veined and have entire margins. The petals are shaped oblong-elliptic to narrowly elliptic and have acute to shortly acuminate apices. The petals are 3-veined and have erose to irregularly denticulate and sometimes entire margins. The petals measure 5.7-7.0mm long and 1.8-3.0mm wide. The labellum is 3-nerved, 3-lobed and not firmly attached to the column. The labellum measures 5.0-5.5mm long and 1.1-1.2mm wide. The side lobes are divaricate and shaped narrowly triangular. The side lobes measure 1.0-1.1mm long. The side lobe upper margins are minutely erose to irregularly dentate. The mid-lobe is shaped obovate, ovate-elliptic, broadly obtrullate or subcordate and has an acute to acuminate or rounded and mucronate apex. The margins of the mid-lobe are uneven to minutely erose. There are two papillose keels than terminate near the apex of the mid-lobe. The keels are joined at the base of the labellum by a transverse ridge. There is an elevated median nerve the joins the keels basally to form an M shape. The keeled transverse ridge sometimes has 2 teeth of either side which can be developed into two erose basal flanges. There is one herbarium specimen where there are no papillae on the keels. The column is gently incurved and measures 2.5-4.0mm long. The column foot is prominent. The apical hood is elongated, shaped triangular-elliptic with an obtuse to acute apex. The apical hood margin is either entire or irregularly tridentate. The stelidia grow upwards from above the base of the column and do not reach the column apex. The stelidia are shaped linear-ligulate or narrowly triangular, falcate and have subacute to acuminate apices.

 

Herbarium Specimens

 

Holotype

 

AMES

 

Specimen 48121 (photo)

 

Other herbarium specimens

 

E

 

SAR

 

BM

 

SING

 

AMES

 

I could not locate the specimen

 

Royal Botanic Gardens Kew (K)

 

Specimen 60402.000

Specimen 60401.000

 

National Herbarium Netherlands, Leiden (L)

 

Specimen L0322437

Specimen L0322438

Specimen L0322439

 

Scent

 

No

 

Flowering Season

 

Flowering plants have been collected in the wild from April, July, August, September and December.

 

Culture

 

I do not think this species is in cultivation

 

Similar Species

 

Dendrochilum dewindtianum

Dendrochilum geesinkii (see this page for the differences)

 

Other Information

 

Ames wrote “Mature pseudobulbs are wanting in the material form which the description was made. D. crassifolium is most closely related to D. kamborangense Ames, from which it differs in the obtuse leathery leaves, in the lateral and middle lobes of the lip, and in the appendages of the column. D. persipicabile is also nearly related, but sufficiently distinct in the lobing of the lip” (Ames 1920).

 

Jeffrey Wood wrote that this species is very similar to Dendrochilum dewindtianum and is equally as variable. Some herbarium specimens can be difficult to tell apart (Wood 2001). The fleshy and tough leaves of Dendrochilum crassifolium are the best way to tell the two species apart.

 

The epithet refers to the thick and fleshy leaves.

 

Reference

 

AMES, Oakes. 1920, Illustrations and studies of the Family Orchidaceae Facsimile 6 The Orchids of Mount Kinabalu British North Borneo, Ames Botanical Laboratory, North Easton, Massachusetts, Boston.

 

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. 12 February 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 12 February 2009.