Accepted name: Dendrochilum hamatum Schltr., Repert. Spec. Nov. Regni Veg. 9: 340 (1911)



Subgenus – Platyclinis. Section – Platyclinis.


 
 
The photo above was taken by Karl Sengahs and is reproduced on this website with the permission of the Swiss Orchid Foundation at th herbarium of Jany Renz. Thanks to Jeffrey Wood for identifying this for me. 
 

Synonyms

 

None

 

Origin in the Wild

 

Kalimantan and Sarawak

 

Elevation in the Wild

 

Not known

 

Habitat in the Wild

 

Plants have been collected near Undup in Sarawak's Sri Aman District and from an unknown locality in Kalimantan.

 

Nothing else is known about the habitat this plant has been found in.

 

The Plants Description

 

The pseudobulbs cluster on an elongated rhizome that can reach a length of 10cm. The pseudobulbs are spaced 1.0-1.5cm apart along the rhizome, and are shaped cylindrical. The pseudobulbs measure 1.0-1.5cm long and 0.4cm in diameter. The leaves are petiolate; the petiole measures 0.5-1.5cm long. The leaf blades are linear-ligulate and have acute apices. The leaf blades measure 3.5-9.5cm long and 0.3-0.4cm wide.

 

The Inflorescence

 

The inflorescence is synanthous. The peduncle is erect and measures c1.7-4.0cm long. The rachis is erect and measures 3.5-5.5cm long. The flowers alternate distichously and are spaced 3.0-4.0mm apart. There are no appressed non-floriferous bracts at the base of the rachis.

 

The Flowers

 

Between 10 and 16 flowers have been recorded growing on an inflorescence (Wood 2001). The sepals and petals are lemon-yellow and have white bases, the labellum is darker lemon-yellow, darker mustard yellow basally or whitish, the keels are pale lemon. The column is lemon yellow and the apical hood margins and stelidia are white Wood 2001). The sepals and petals spread widely. The dorsal sepal is shaped narrowly elliptic or oblong-elliptic and has an acute apex. The dorsal sepal measures 5.0mm long and 1.0-1.5mm wide. The dorsal sepal is three veined and has an entire margin. The lateral sepals are shaped slightly obliquely narrowly elliptic and have acute apices. The lateral sepals measure 4.2-5.0mm long and 1.2-1.8mm wide. The lateral sepals are three veined and have entire margins. The petals are shaped obliquely narrowly elliptic or ligulate, slightly falcate and have acute apices. The petals measure 4.0-4.2mm long and 0.9-1.2mm wide. The petals are three veined and have minutely serrulate margins. The labellum is shortly clawed, deflexed from the claw, three veined and entire. The labellum measures 2.5-3.2mm long and 1.8-2.0mm wide. The labellum has irregularly toothed margins on the proximal half and entire margins on the apical half. The labellum is shaped oblong-ligulate to subpandurate and has a subacute apex; the labellum is narrower at its middle. There are two short keels that are not joined at the base. The column is curved and measures 2.1-2.5mm long. The column foot is prominent. The apical hood is prolonged into a rounded apex with an entire or shortly five dentate margin. The stelidia grow outwards from the top of the column, at the base of the hood, and are shorter than the column apex. The stelidia are deflexed, upturned at their apex and hamate.

 

Herbarium Specimens

 

Holotype

 

B (Destroyed)

 

Isotype

 

AMES

 

Specimen 98764 (drawing of the type)

FI

 

Other herbarium specimens

 

Royal Botanic Gardens Kew (K)

 

Specimen 61375.000

Specimen 61370.000

Specimen 61376.000

 

National herbarium Netherlands (L)

 

Specimen L0322532

 

BO

 

Scent

 

I could find no record.

 

Flowering Season

 

Flowering plants have been collected in the wild during January and September.

 

Culture

 

I do not think this species is in cultivation

 

Similar Species

 

Dendrochilum pubescens

 

Other Information

 

This species was only known from its original collection by Odoardo Beccari until Phillip Cribb recently photographed this species growing at the Bogor Botanical Garden in Java. The plant had been collected in West Kalimantan.

 

The plant resembles Dendrochilum pubescens by its similar habit, labellum morphology and flower colour. Dendrochilum hamatum differs by its leaves, the hamate stelidia and the floral pubescence found on Dendrochilum pubescens (Wood 2001).

 

The epithet refers to the hook on the apex of the stelidia.

 

Reference -

 

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

 

SCHLECHTER, R. 1911, Repert. Spec. Nov. Regni Veg. 9: 217-266

 

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

 

World Checklist of Selected Plant Families. 24 July 2009. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 24 July 2009.