Accepted name: Dendrochilum wenzelii Ames, Orchidaceae 5: 65 (1915).



Subgenus – Acoridium. Section – Acoridium.


 

 

Synonyms

 

Acoridium wenzelii (Ames) Ames, Orchidaceae 7: 82 (1922).

 

Origin in the Wild

 

Luzon, Mindanao and Visayas

 

Elevation in the Wild

 

500-1800 metres

Ames wrote (1915) that a plant had been collected at 300 metres.

 

Habitat in the Wild

 

The type was collected near Jaro on Leyte in the Visayas.

 

In Luzon this plant has been collected in Albay Province on Mount Malinao. In Camarines Sur this plant has been collected on Mount Isarog. In Kalinga-Apayao province this plant has been collected in Balbalan and on Mount Sulu. In the Nueva Vizcaya Province this plant has been collected along the Dalton Pass.

 

On Leyte this plant has been collected at Buenavista near Jaro, Mount Abucayan and Mount Suiro.

 

On Mindanao this plant has been collected from Bukidnon Province in the Katanglad Mountains.

 

Dendrochilum wenzelii grows as an epiphyte and has been recorded as growing in mossy forest and on ridges.

 

The Plants Description

 

The pseudobulbs cluster along the rhizome and are shaped slenderly terete-fusiform. The pseudobulbs measure 1.3-3.7cm long and 0.2-0.4cm in diameter. The pseudobulbs are covered by 4-5 cataphylls while they are growing. The cataphylls disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate but not distinctly. The leaf blades are shaped narrowly linear and have acute apices. The leaves measure 13.2-43.8cm long and 0.2-0.4cm wide. The leaves have one distinct nerve.

 

The Inflorescence

 

The peduncle is enclosed for 1/3 of its length by the subtending leaf. The peduncle is suberect to curved and measures 8.5-33cm long. The peduncle is subquadrate in cross-section and finely setose. The rachis is nodding and measures 3.5-8.7cm long. The flowers alternate distichously and are spaced 1.5mm apart. There are 4-6 appressed non-floriferous bracts at the base of the rachis. The flowers open from the proximal and sometimes central section of the rachis.

 

The Flowers

 

The flowers are most commonly bright red but can be brown or greenish-yellow. Up to 30 flowers can grow on an inflorescence (Cootes 2001).  The sepals and petals spread widely. The dorsal sepal is shaped oblong and has an obtuse to acute apex. The dorsal sepal measures 3.2-4.4mm long and 1-1.6mm wide. The dorsal sepal is three veined and has an entire margin. The lateral sepals are shaped obliquely ovate and have acute apices. The lateral sepals measure 3.4-4.8mm long and 18-2.3mm wide. The lateral sepals are three veined and have entire margins. The petals are shaped oblong to broadly elliptic-obovate and have subacuminate to acute apices. The petals measure 1.9-3mm long and 0.7-1.5mm wide. The petals are three veined and have entire margins. The labellum is porrect and is 3-lobed. The labellum measures 0.6-1mm long and 1.8-2.4mm wide. The labellum is obscurely three veined, glabrous and has entire margins although the side lobes are sometimes slightly dentate. The side lobes are suberect, shaped broadly or falcately oblong and have obtuse apices; the side lobes distinctly exceed the mid-lobe. The mid-lobe is very small, shaped triangular and has an acuminate apex. There are two tiny calli located at the base of each side lobe that is shaped pyramidal, there is no median callus. The column is straight, suberect and measures 0.6-1.2mm long. The column is somewhat hooded. Stelidia and column foot are absent.

 

Herbarium Specimens

 

Lectotype

 

AMES

 

Specimen 18856 (photo)

 

Isotype

 

BM

C

Royal Botanic Gardens, Kew (K)

 

I could not locate the specimen

National Herbarium Netherlands (L)

 

Specimen L0058483 (photo)

New York Botanical Garden (NY)

 

Specimen - 39518 (Isolectotype) (photo)
 
P

SING

US

 

Other herbarium specimens

 

National Herbarium Netherlands (L)

 

Specimen L0322813

Specimen L0322814

Specimen L0322815

 

Royal Botanic Gardens, Kew (K)

 

Specimen K000364848

Specimen 71265

Specimen 71111

 

Scent

 

No

 

Flowering Season

 

In northern hemisphere cultivation plants flower in the spring but the inflorescences appear during winter. In Australia this species flowers during the winter (Cootes 1995 et al). The flowers last for approximately three weeks. Flowering plants have been collected in the wild during February, March, May and December.

 

Culture

 

This species is very common in cultivation. I have seen plants in Australia, South Africa, USA, Brazil, The Philippines and Europe.

 

My experience is that this plant nearly doubles in size every year. I keep this plant in 70-80% shade and a plant can easily grow with night time temperatures as low as 6 degrees Celsius (Cootes and Banks 1995). I grow my plant outside most of the year. This species is very prone to 'sulking' if its roots are disturbed. This species is sensitive to water quality. I do not know of anyone who grows this species mounted.

 

I fertilize very weakly every second water and grow this plant sitting in water year round.

 

Many plants are incorrectly pictured and labelled as Dendrochilum arachnites 'red' (see other information below)

 

Similar Species

 

Dendrochilum javierii

Dendrochilum banksii (see this page for the differences)

Dendrochilum saccolabium

Dendrochilum pseudowenzelii (see this page for the differences)

 

Other Information

 

Ames considered this species to be similar to Dendrochilum graminifolium and wrote that it differed by its almost absent mid-lobe. L.O. Williams compared Dendrochilum wenzelii to Dendrochilum saccolabium a comparison that Henrik Pederson agreed with. Pedersen grouped (1997) Dendrochilum wenzelii with Dendrochilum saccolabium and Dendrochilum javierii.

 

The leaf apices are needle sharp.

 

Wenzel's plant that he collected in 1914 at Jaro on Leyte had greenish-yellow flowers.

 

This plant is very often sold as Dendrochilum arachnites 'red' although it looks nothing like Dendrochilum arachnites. I have seen Dendrochilum wenzelii sold, pictured and grown as D. arachnites. Dendrochilum arachnites does not have long sharp needle like leaves but more defined pseudobulbs with wider paler green leaves. The Dendrochilum arachnites flowers have much longer lateral sepals and the flower colour is very pale yellow-green and never red. This species has similar characteristics as Dendrochilum javierii.

 

The epithet refers to the first collector of this plant.

 

Reference -

 

AMES, Oakes. 1915, Illustrations and studies of the Family Orchidaceae Facsimile 5, Ames Botanical Laboratory, North Easton, Massachusetts, Boston.

 

COOTES, Jim. The Orchids of the Philippines, 2001. Timber Press, USA

 

COOTES, Jim. BANKS, David. 1995, The genus Dendrochilum A guide to the species in cultivation, Orchids Australia, AOC

 

PEDERSEN, Henrik. 1997, The Genus Dendrochilum (Orchidaceae) in the Philippines - A Taxonomic Revision. Opera Botanica, Denmark

 

World Checklist of Selected Plant Families. 04 February 2008. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 04 February 2008.