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

 

Accepted name: Dendrochilum parvulum var. strictiforme (Ames) H.A.Pedersen, Opera Bot. 130: 20 (1997)

 


Subgenus – Acoridium. Section – Acoridium.


 
 
This drawing is by Oakes Ames and is from his Facsicle 2 in 1908.
 
 

Synonyms

 

var. parvulum

 

Acoridium venustulum Ames, Proc. Biol. Soc. Wash. 19: 147 (1906).

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

Acoridium parvulum Ames, Proc. Biol. Soc. Wash. 19: 146 (1906).

 

var. strictiforme

 

Acoridium strictiforme Ames, Proc. Biol. Soc. Wash. 19: 147 (1906).

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

 

Origin in the Wild

 

Luzon

 

Elevation in the Wild

 

var. parvulum

 

1400 - 2500 metres

 

var. strictiforme

 

1995-2150 metres

 

Ames described a plant that was found at 1400 metres (Ames 1909)

 

Habitat in the Wild

 

var. parvulum

 

This species has been recorded as an epiphyte of mossy forest and of open areas on solitary trees.

 

This species has been collected in Bataan Province from the Lamao River near Mount Mariveles. Benguet Province from Bukod, Mount Santo Thomas, Mt Sinapsapan and Mt Tonglon; Cagayan Province on Mt Balatongan and Mt Cagua; Ifugao province, Mt Himi-o, Mt Pimmage and Mt Polis; Kalinga-Apayao Province on Mt Sulu; Laguna on Mt Banahao; Quezon Province on Mt Camatis; Rizal Province on Mt Lumutan.

 

var. strictiforme

 

This variety has been recorded growing as an epiphyte in mossy forest. Plants have been collected from Benguet Province, Pauai, Mount Pulog, Mount Pulogloco, and Mount Sinapsapan and from Ifugao Province on Mount Himi-o, Mount Pimmage and Mount Polis.

 

The Plants Description

 

var. parvulum

 

This is a small clumping Dendrochilum. The pseudobulbs are shaped fusiform to somewhat obpyriform and measure 0.2-4.6cm long and 0.1-0.6mm in diameter. The pseudobulbs are covered by c4 cataphylls while they are growing. The cataphylls disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 0.1-0.4cm long. The leaf blades are shaped linear-oblong and have obtuse to truncate apices. The leaf blades measure 1.2-8.5cm long and 0.2-1.2cm wide. The leaves have 3 distinct nerves.

 

var. strictiforme

 

This small species has pseudobulbs that cluster on a short rhizome. The pseudobulbs are shaped fusiform to ellipsoid and measure 0.5-3.1cm long and 0.1-0.3cm in diameter. The pseudobulbs are covered by c4 cataphylls while they are growing. The cataphylls disintegrate into persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 0.1-1.1cm long. The leaf blades are shaped linear-oblong and have acute to obtuse apices. The leaf blades measure 1.5-8.3cm long and 0.2-0.4cm wide. The leaves are three veined.

 

The Inflorescence

 

var. parvulum

 

The inflorescence is synanthous and is free from the subtending leaf at the time of flowering. The peduncle is suberect to curved and measures 1.5-10.4cm long. The rachis is nodding to pendent and measures 1.4-6.8cm long. The flowers on the rachis are distichously arranged, slightly flexuose and are spaced c1mm apart. There are 1-2 non-floriferous bracts. The flowers open from the proximal part of the rachis.

 

var. strictiforme

 

The inflorescence is synanthous and is free from the subtending leaf at the time of flowering. The peduncle is suberect to curved and measures 1-8.8cm long. The rachis is probably nodding and measures 0.8-3.2cm long. The flowers on the rachis are distichously arranged, slightly flexuose and are spaced c1mm apart. There are 1-2 non-floriferous bracts. The flowers open from the proximal part of the rachis.

 

The Flowers

 

var. parvulum

 

The flowers are most often white but can be yellow; flowers have been recorded with purple markings on the labellum. Ramos field notes described the flowers as nearly white (Ames 1909). Up to 20 flowers grow on an inflorescence (Cootes 2001). The dorsal sepal is shaped lanceolate and has an acuminate apex. The dorsal sepal measures 2.5-3.6mm long and 0.7-1mm wide. The dorsal sepal is one veined and has an entire margin. The lateral sepals are oblique and shaped lanceolate (Ames), elliptic to narrowly ovate (Pedersen) and have acute or acuminate apices. The lateral sepals measure 2.3-3.4mm long and 0.9-1.5mm wide. The lateral sepals have entire margins and are one veined. The petals are shaped linear-lanceolate and have acute (Ames), subacute to acuminate (Pedersen) apices. The petals are one veined and have entire margins. The petals measure 2.4-3.4mm long and 0.5-0.8mm wide. The labellum is porrect, 3-lobed and measures 0.5-0.8mm long and 1.1-1.7mm wide. The side lobes are shaped oblong-falcate and have rounded apices. The side lobes exceed the mid-lobe. The mid-lobe is wider than it is longer, is shaped broadly oblong and has a retuse and mucronate apex. The lateral calli are at the base of the side lobes and are shaped oblongoid. The median callus is in the centre of the disc and is smaller. The column is slightly incurved and measures 0.6-0.9mm long. The column is hooded at its apex. The anther cap is shaped broadly-orbicular from its upper view and rounded from its front.

 

var. strictiforme

 

The flowers are white (Pedersen 1997) and (Ames 1909). The dorsal sepal is shaped linear-lanceolate and has an acuminate apex. The dorsal sepals measures 2.4-3.8mm long and 0.7-0.9mm wide. The dorsal sepal is one veined and has an entire margin.  The lateral sepals are oblique, shaped elliptic-lanceolate to ovate and have acute or acuminate apices. The lateral sepals are shaped 2.2-3.6mm long and 0.9-1.5mm wide. The lateral sepals have entire margins and are one veined. The petals are shaped linear-lanceolate and have acute (Ames) acute to acuminate (Pedersen) apices. The petals are 1-veined and have entire margins. The petals measure 1.9-3.7mm long and 0.5-0.7mm wide. The labellum is porrect, 3-lobed and measures 0.5-0.7mm long and 1.0-1.4mm wide. The side lobes are shaped oblong-falcate and have rounded to obtuse apices. The side lobes exceed the mid-lobe. The mid-lobe is 3-lobed with a porrect and triangular shaped mid-lobe, the 2 lateral lobes are shaped broadly oblong and have rounded and refluxed apices. The lateral calli are at the base of the side lobes and are shaped oblongoid. The median callus is in the centre of the disc and is smaller. The column is slightly incurved and measures 0.5-0.9mm long. The column is hooded at its apex. The anther cap is shaped broadly-oblong from its upper view and truncate from its front.

 

Herbarium Specimens

 

Holotype

 

Philippine National Herbarium (PNH)

 

Specimen - destroyed (Dendrochilum parvulum)

Specimen - destroyed (Dendrochilum parvulum var. strictiforme)

 

 

Isotype

 

AMES

 

Specimen 46 (photo)

Specimen 18909 (photo) (Acoridium venustulum)

Specimen 58 (photo) (Acoridium strictiforme) (var. strictiforme)

 

 

 

Other herbarium specimens

 

National Herbarium Netherlands (L)

 

Specimen L0322687

Specimen L0322689

Specimen L0322690

Specimen L0322692 (var. strictiforme)

 

Royal Botanic Gardens, Kew (K)

 

Specimen 73927.000

Specimen 62267.000

Specimen 60733.000 (var. strictiforme)

 

 

Scent

 

var. parvulum

 

Yes, but is faint.

 

var. strictiforme

 

Ames mentioned that this species was fragrant.

 

Flowering Season

 

var. parvulum

 

Flowering plants have been collected in the wild during January, from March to July and October to January.

 

Plants in cultivation in the northern hemisphere flower in late winter and early spring. Plants in Australian cultivation have been known to flower during winter.

 

var. strictiforme

 

Flowering plants have been collected in the wild from June to December and during January.

 

Culture

 

var. parvulum

 

This species is commonly found in cultivation globally.

 

var. strictiforme

 

I do not think this species is in cultivation

 

Similar Species

 

Dendrochilum asperum

Dendrochilum microchilum

Dendrochilum mindanaense

Dendrochilum quadrilobum

Dendrochilum binuangense

Dendrochilum loheri

Dendrochilum pulogense

 

Other Information

 

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

 

Oakes Ames said that Acoridium strictiforme differed from Acoridium parvulum by having one vein on the petals, its strict and rigid habit and its acute leaves. Dendrochilum parvulum var parvulum, however, is usually one veined on its petals.  Oakes Ames compared this species to Dendrochilum microchilum (Ames 1908). Henrik Pedersen agreed and placed Dendrochilum parvulum in a group with Dendrochilum asperum, D. microchilum, D. parvulum var strictiforme, D. mindanaense, D. quadrilobum, D. binuangense and D. loheri. 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.

 

Acoridium venustulum was described as a yellow flowered species similar to this species. L.O. Williams reduced Acoridium venustulum to a synonym. The holotype of Acoridium venustulum was destroyed at the Philippine National Herbarium.

 

Oakes Ames compared this species to Dendrochilum microchilum. Henrik Pedersen agreed and placed Dendrochilum parvulum in a group with Dendrochilum asperum,

D. microchilum, D. parvulum var strictiforme, D. mindanaense, D. quadrilobum, D. binuangense and D. loheri. 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.

 

Henrik Pedersen reduced Dendrochilum strictiforme to a variety of Dendrochilum parvulum in 1997 because the 2 species could only be distinguished by the shape of their labellum.

 

Below is a copy of the keys Henrik Pedersen wrote in his 1997 revision

 

1              Leaf blade 0.2-1.2cm wide, usually rounded to obtuse. Side lobes of labellum slightly exceeding the mid-lobe; mid lobe broadly oblong (-quadrate), apically emarginate with a short apiculum in the sinus………………………………………………………………...  var parvulum

2              Leaf blade 0.2-0.4(-0.5) cm wide, usually acute. Side lobes of labellum distinctly exceeding the mid lobe; mid lobe 3-lobed with the median lobe distally exceeding the lateral ones……………………..var strictiforme

 

The epithet refers to the small habit of the plant.

 

Reference -

 

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

 

AMES, Oakes. 1909, Notes on the Philippine Orchids with Descriptions of New Species, Philippine Journal of Science, Manila, Philippines.

 

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. 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.