Accepted name: Dendrochilum oliganthum (Ames) Pfitzer in H.G.A.Engler (ed.), Pflanzenr., IV, 50 II B 7: 117 (1907)

Subgenus – Acoridium. Section – Acoridium.


 
 

Synonyms

 

Acoridium oliganthum Ames, Proc. Biol. Soc. Wash. 19: 150 (1906).

 

Origin in the Wild

 

Luzon

 

Elevation in the Wild

 

1890 - 2150 metres

 

Habitat in the Wild

 

This species has been collected in Benguet Province on Mount Data and Mount Sinapsapan. Nothing is known about its habitat.

 

The Plants Description

 

This very small tufted species produces pseudobulbs that cluster on a short rhizome. The pseudobulbs are shaped ellipsoid and measure 0.4-0.6cm long and 0.2-0.4cm in diameter. The pseudobulbs are covered by c3 cataphylls while they are growing. The cataphylls disintegrate into non-persistent fibres as the pseudobulbs mature. The leaves are petiolate; the petiole measures 0.1-0.4cm long. The leaf blades are shaped oblong-lanceolate and have obtuse apices. The leaf blades measure 1.4-3cm long and 0.3-0.7cm wide. The leaves are thin textured and have 3-5 distinct nerves on them the two lateral nerves are 0.5mm from the margin.

 

The Inflorescence

 

The inflorescence is synanthous and free from the subtending leaf at the time of flowering. The peduncle is suberect and measures 1.8-3.2cm long. The rachis is nodding and measures 1.8-3cm long. The flowers are spaced 1-2mm apart. There are 1 or 2 appressed non-floriferous bracts on the rachis. The flowers open from the distal section of the rachis.

 

The Flowers

 

Between 6 and 11 flowers have been recorded growing on an inflorescence. The flower colour is described by Ames as brownish-red and orange when dry (Ames 1908). The dorsal sepal is shaped obovate-oblong and has a rounded to obtuse apex. The dorsal sepal measures 2.9-3mm long and c1.6mm wide. The dorsal sepal has an entire margin and is three veined. The dorsal sepal is finely setose. The lateral sepals are shaped obliquely orbicular-quadrate and have obtuse apices. The lateral sepals measure c2.1mm long and c2.3mm wide. The lateral sepals are three veined, have entire margins and are finely setose. The petals are shaped obliquely obovate-flabellate and have rounded apices. The petals measure c2.1mm long and c2.3mm wide. The petals have entire margins are three veined. The labellum is porrect and obscurely 3-lobed. The labellum measures 0.7-0.8mm long and 1.7-1.8mm wide. The labellum margins are entire. . The side lobes are erect and embrace the column. The side lobes are shaped oblong with rounded apices. The side lobes are subequal in length to the mid-lobe. The mid lobe is subtriangular and has a subacute to obtuse apex. There are 2 lateral calli that are shaped transversely oblongoid and located at the bases of the side lobes. The median callus is smaller, shaped oblongoid and in between but in front of the 2 lateral calli. The column is suberect, somewhat incurved and measures 0.5-0.6mm long. The anther cap is hood at the apex. The anther cap is broadly rectangular in outline.

 

Herbarium Specimens

 

Holotype

 

Philippine National Herbarium (PNH)

 

Specimen - destroyed

 

 

Isotype

 

AMES

 

Specimen 43 (photo)

 

Scent

 

I could find no record.

 

Flowering Season

 

Flowering plants have been collected in the wild during October.

 

Culture

 

I do not think this species is in cultivation

 

Similar Species

 

Dendrochilum ocellatum

 

Other Information

 

Henrik Pedersen considered Dendrochilum oliganthum to be a sister species to Dendrochilum ocellatum (Pedersen 1997). Pedersen also wrote that there is a close affinity to Dendrochilum marginatum, D. rhombophorum, D. philippinense, D. macgregorii and D. foxworthyi. Dendrochilum ocellatum and oliganthum can be distinguished from these other species by their fewer flowered inflorescence, better developed calli and different shaped labellum (Pedersen 1997).

 

Oakes Ames wrote in his facsimile 2 "In the herbarium of the Bureau of Science at Manilla this species and Dendrochilum ocellatum are mounted on the same sheet. Both species were collected by Mr. Merrill at the same time. Only four plants were found, two of each species. D. oliganthum belongs to that group of species which have the lateral lobes of the lip much smaller, than the middle lobe, and which merge with D. whitfordii and D. ocellatum" (Ames 1908).

 

 

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. 19 November 2008. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 19 November 2008.