Accepted name: Dendrochilum microchilum (Schltr.) Ames, Orchidaceae 2: 87 (1908)

Subgenus – Acoridium. Section – Acoridium.


 
 

Synonyms

 

Platyclinis microchila Schltr., Bull. Herb. Boissier, II, 6: 302 (1906).

Acoridium microchilum (Schltr.) Ames, Orchidaceae 7: 81 (1922).

Acoridium tenue Ames, Proc. Biol. Soc. Wash. 19: 145 (1906).

Dendrochilum tenue (Ames) Pfitzer in H.G.A.Engler (ed.), Pflanzenr., IV, 50 II B 7: 116 (1907).

 

Origin in the Wild

 

Mindanao, Luzon

 

Elevation in the Wild

 

500 - 2830 metres

 

Habitat in the Wild

 

Ames wrote that this species has been collected on Mindanao from Mount Malindang and along the trail to Mount Apo growing on mossy trees.

 

This species has been collected in Luzon from Bataan Province along the Lamao River, Mt Mariveles. Benguet Province. Camarines Sur Province on Mount Isarog and the Panagan River. Ifugao Province on Mount Himi-o, Mount Pimmage and Mount Polis. Mountain Province on Bauko. Rizal Province. Mindoro Oriental on Mount Halcon. On Leyte from Buenavista near Jaro, Lake Danao, Mount Janagdan and Mount Mamban. Negros Occidental on the Canlaon Volcano. Negros Oriental, Cuernos de Negros on Mount Malbug. Mindanao, in Bukidnon Province on Mount Lipa; Camiguin; Davao del Sur on Mount Apo; Misamis Occidental Province on Mount Malindang.

 

This species is an epiphyte of mossy cloud forest.

 

The Plants Description

 

The pseudobulbs cluster on a short rhizome. The pseudobulbs are shaped fusiform and measure 0.7-3.5cm long and 0.1-0.3cm 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, the petiole measures 1cm long. The leaf blades are shaped linear-oblong and have obtuse and sometimes minutely mucronate apices. The leaf blades measure 2.0-8.5cm long and 0.2-0.6cm wide. The leaves are 3 veined; the 2 lateral nerves are 0.5mm from the leaf margin.

 

The Inflorescence

 

The inflorescence is synanthous and free from the subtending leaf at the time of flowering. The peduncle is suberect to curved and measures 1.2-11cm long. The rachis is nodding to pendent and measures 2.7-6.3cm long. The flowers alternate distichously, are sometimes flexuose and spaced 1-2mm apart. There are 1-3 non floriferous bracts on the rachis. The flowers open from the proximal section of the rachis.

 

The Flowers

 

The flowers are white to pale yellow, the sepals and petals open widely.  Up to 40 flowers can grow on an inflorescence (Cootes 2001). The dorsal sepal is shaped lanceolate to narrowly ovate and has an acuminate apex. The dorsal sepal measures 1.8-2.9mm long and 0.3-1mm wide. The dorsal sepal has an entire margin and is 1-3 veined. The lateral sepals are shaped linear-lanceolate (Ames) obliquely lanceolate (Pedersen) and have acuminate or acute apices. The lateral sepals measure 1.8-2.8mm long and 0.5-0.9mm wide. The lateral sepals have entire margins and are 1-3-veined; however a one veined sepal is rare. The petals are shaped narrowly lanceolate (Ames) obliquely lanceolate to narrowly ovate (Pedersen) and have acuminate or acute apices. The petals measure 1.5-2.4mm long and 0.4-1mm wide. The petals have entire margins and are one veined. The labellum is porrect and 3-lobed. The side lobes are erect; crescent shaped and have subacuminate apices. The side lobes exceed the mid-lobe. The mid lobe is transversely crescent shaped and has a truncate apex that is apiculate at its centre. The margins on the labellum are entire. There are 2 lateral calli that are located at the base of the side lobes, the lateral calli are shaped oblongoid. The median callus is located at the centre of the disc and along one of the veins; the median callus is located closer to the base than the two lateral calli. The column is suberect, nearly straight and measures 0.4-0.7mm long. The column is hooded at its apex. The anther cap is subquadrate from its upper view and truncate from its front.

 

Herbarium Specimens

 

Holotype

 

AMES

 

Specimen 103239 (photo) (Acoridium tenue)

 

Other herbarium specimens

 

National Herbarium Netherlands (L)

 

Specimen L0322642

Specimen L0322644

Specimen L0322645

Specimen L0322646

Specimen L0322647

Specimen L0322648

Specimen L0322649

Specimen L0322650

Specimen L0322651

Specimen L0322652

Specimen L0322654

 

Royal Botanic Gardens, Kew (K)

 

Specimen 76177.000 (from a cultivated specimen)

Specimen 73153.000

Specimen 72224.000

 

Scent

 

No (from my own experiences)

 

A Kew specimen states that there is a faint sweet scent.

 

Flowering Season

 

Flowering plants have been collected in the wild year round. In northern hemisphere cultivation this species flowers during the spring; the flowers last for approximately 15 days.

 

Culture

 

This species is found in cultivation in Australia, Europe and North America although it can be a challenge to find.

 

This species divides easily but takes time to adjust after the division.

 

Similar Species

 

Dendrochilum asperum (see this page for the differences)

Dendrochilum parvulum var parvulum

Dendrochilum parvulum var strictiforme

Dendrochilum pulogense

Dendrochilum mindanaense

Dendrochilum quadrilobum

Dendrochilum binuangense (see this page for the differences)

Dendrochilum loheri

 

Dendrochilum curranii

Dendrochilum tenuifolium (see this page for the differences)

 

Other Information

 

Schlechter named this species Platyclinis microchila in 1906 shortly before Oakes Ames named Acoridium tenue, also in 1906. In 1907 Acoridium and Platyclinis were transferred into Dendrochilum as sections. Oakes Ames therefore named this species Dendrochilum microchilum in his facsimile 2. Oakes Ames still considered Dendrochilum tenue and D. microchilum to be different as this time. L.O. Williams reduced Acoridium tenue as a synonym in 1951. At this time L.O. Williams transferred Acoridium venustulum from being a synonym of Dendrochilum microchilum to a synonym of Dendrochilum parvulum. Ames mistakenly placed Acoridium venustulum as a synonym of Dendrochilum microchilum resulting in specimens that were mistakenly misidentified.

 

Oakes Ames compared this species to Dendrochilum parvulum. Henrik Pedersen agreed and placed Dendrochilum microchilum in a group with those others named above. They are grouped because of the similarities of the labellum, vegetative similarities and a peduncle that is free from the subtending leaf at the time of flowering.

 

I have used Henrik Pedersen’s measurements rather than Schlechter or Oakes Ames; the reason being is that more specimens have been collected since its original collection in 1906.

 

The epithet refers to the small labellum.

 

Reference

 

AMES, Oakes. 1908, Illustrations and studies of the Family Orchidaceae Facsimile 2, Ames Botanical Laboratory, North Easton, Massachusetts, Boston.

 

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

 

World Checklist of Selected Plant Families. 01 November 2008. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 01 November 2008.