WEST PAPUA – In February 2020, a team from West Papua’s Natural Resources Conservation Centre of the Ministry of Environment & Forestry, Republic of Indonesia (BBKSDA Papua Barat) and staff from the Indonesia team of Fauna & Flora International visited its highest mountain, Mount Nok, an 880 m high extinct volcano.
The summit zone of this mountain is the type locality of Dendrobium azureum Schuit., a striking, blue-flowered species that had not been seen for almost 80 years since it was first collected in 1938 by British entomologist Evelyn Cheesman.
It was one of the highlights of the 2020 expedition to find this beautiful orchid (Knight, 2022), although it had already, and for the first time, been photographed by FFI staff in the same locality in 2016.
Despite its conspicuous, brightly coloured flowers, Dendrobium lancilabium subsp. lancilabium is poorly represented in herbaria, with currently only five known collections. The team has been unable to find any photographs of living plants.
It was first described by J.J. Smith (1934: 198) based on a single specimen collected by the eminent biologist Ernst Mayr in July 1928 on Mt. Wondiwoi in the Wandamen Peninsula of northwestern New Guinea.
It was later also found in the Nettoti, Tambrauw and Tokhiri mountains in the Vogelkop Peninsula of western New Guinea and has been collected between 1000 and 1980 m elevation.
Surprisingly, it has not yet been found in the Arfak Mountains, the largest mountain range in the area, although it may be expected to occur there.
The flower colour is somewhat variable; it has been described as orange, orange-red, blood-red, brilliant red, or pinkish orange with a yellow lip tipped pinkish orange.
The typical subspecies may be recognised by the slender, unbranched stems, short and broad leaves with a distinct contraction in the upper half, one(sometimes two according to Smith)-flowered inflorescences, and an oblanceolatesubspathulata, acute lip without a callus. The ovary is indistinctly triangular (semiterete?) in cross-section.
The specimens from Waigeo Island have flowers that are quite similar to those of subsp. lancilabium, differing only in the relatively minor details mentioned in the diagnosis.
In at least one flower of the material from Waigeo, the lip had a distinct V-shaped callus on the claw, but this could not be seen on all the, sometimes damaged, lips examined.
Such a callus has not been described from subsp. lancilabium, but it could similarly have been missing or overlooked.
In living flowers of subsp. wuryae, the apical part of the lip is at almost right angles with the claw; it is not known if this is also the case in subsp. lancilabium. This is a character that may easily disappear in a pressed and dried flower.
The main differences between material seen of subsp. lancilabium and the material from Waigeo are the branching stems and much narrower leaves in the latter. The leaves on the branches are much smaller than those on the main stems.
Since having branching or non-branching stems appears to be an important and mostly reliable distinction between species in sect. Calyptrochilus, the team prefers to treat the Waigeo material as a separate taxon.
In view of the great similarities between the flowers of the two entities, and also taking into account the characteristic contraction in the apical part of the leaf, which in a weaker form can also be seen in subsp. wuryae, the team considers that the latter is not distinct enough to be considered a separate species but at the same time too different to be lumped with subsp. lancilabium.
A status as a distinct subspecies for this attractive orchid seems appropriate.
Indonesian
Chinese (Simplified)
English
German