Introduction

In Botany, two main states of mind occur: a botanist is either a splitter, or a lumper. The first, when engaging in taxon delimitation, attributes much importance to deviations from the general pattern, and is inclined to reflect that in recognising a large number of genera and species. The second tends more to consider general patterns, and allows for deviations in taxa, without immediately describing a not entirely matching plant as a new taxon. As a consequence, the number of orchid genera occurring all over the world can not exactly be stated. An estimate is that this number lies between 820 and 1042. Of these, 132 (or a few dozen more when you ask a splitter) have wild representatives in New Guinea.

A conservative estimate for the total number of orchid species is about 25,000 known species world wide (Hassler, 2001; Royal Botanic Gardens, Kew, 2003). This makes orchids the largest family of flowering plants on this word.

New Guinea is the largest tropical island in the world, and of all islands second in size only to Greenland. The area richest in orchid species is the northern Andes (Colombia, Ecuador, Peru). With about 2800 species, New Guinea is a very close second. As many as 2800 described species occur there, accounting for about eleven percent of the world’s orchid flora (Schuiteman & de Vogel 2001).

Surprisingly, only very few orchidologists worked on this amazing orchid flora, and about 90% of all species were described before World War II by only 5 specialists. The most important and productive were R. Schlechter and J.J. Smith.

Family classification

Modern molecular techniques have indicated that orchids can be subdivided in 5 subfamilies (Pridgeon et al. 1999): Apostasioideae, Vanilloideae, Cypripedioideae, Orchidoideae, and Epidendroideae. All subfamilies occur in New Guinea.

The first three are small in numbers, and except for the Vanilloideae they are quite deviating from the morphological pattern known from “real” orchids: they have two or three anthers. All other orchids possess only one anther.

The Orchidoideae in New Guinea contain 31 genera with some 185 species. Members of this subfamily are mainly terrestrials. The genus Corybas shows an extensive radiation of c. 45 endemic species in New Guinea; it occurs from India to New Zealand, with about 125 species.

The Epidendroideae are by far the most significant subfamily in New Guinea, with perhaps as many as 2600 species in 93 genera. Most are epiphytes. 21 subtribes occur here, with the Bulbophyllinae, the Dendrobiinae, the Glomerinae and the Thelasiinae represented by large numbers of species. The largest genus is Bulbophyllum which comprises about 600 species in New Guinea (about 1500 world wide), followed by Dendrobium (400), Phreatia (130), Glomera (100), Taeniophyllum (90), Malaxis (90), Oberonia (90), and Liparis (80). The island of Borneo, in comparison, has c. 1400 described species. Here Bulbophyllum has 215 species, Dendrobium 145, Phreatia 7, Glomera 0, Taeniophyllum 12, Malaxis 32, Oberonia 27, and Liparis 37.

Distribution and habitat

Orchids occur all over the world, but not in the polar regions (Dressler 1981). The family is essentially tropical, only c. five percent of the species occur in temperate regions, most of these are terrestrials. They do not favour arid regions; in contrast they have an astonishing diversification in everwet climates where temperatures are moderate at all times, mainly in the mountains between c. 900 and 2500 m above sea level. About eighty percent of the orchid species of New Guinea are epiphytes; world wide this is c. 75%.

Endemism

With almost 3000 taxa described, New Guinea is about twice as rich or more than that compared with all other countries or island groups in Southeast Asia. About 95 percent of the New Guinea orchid species is endemic to this island and occur nowhere else! For the Philippines this percentage is 74%, for Borneo 55% and for Java only 31%. (Agoo et al. 2002). In complete contrast to endemism at species-level, endemism at genus level in New Guinea is relatively low.

Within the island many species are widespread, especially those in the central mountain range which runs almost from the western to the eastern tip of the island. Other species are, however, not quite so widespread. Some have ranges that span several hundreds of kilometres, but a very large number is known so far from one locality only (which is probably due to the very low collecting density).

The central mountain range does not seem an effectively barrier against dispersal from North to South or the other way round. Most widespread lowland species are found both North and South of this range.

Gaps in floristic documentation and knowledge

New Guinea orchids are still poorly known. Many species are known only from the type collection, or from a single locality. Several other species have been collected only twice but in localities hundreds of kilometres apart, an indication of our scanty knowledge of their real distribution. Further, the collecting density for Papua New Guinea is about 5 times higher than for Indonesian Papua where only about one percent of the total surface area has ever been visited by a botanist.

Natural history

Compared with neighbouring areas, the orchid flora of New Guinea shows some special features. The unusual high radiation of certain groups within the family is striking, the most prolific example being the genus Bulbophyllum. Further, many orchids here are very small plants. The proportion of so called ‘miniature orchids’ is probably highest in New Guinea. And an extraordinary large number of orchids in New Guinea have flaccid and much elongated pendulous stems.

Bird-pollinated orchids, although not restricted to New Guinea, are here probably most frequent. The characters are: flowers opening during the day; horizontal or hanging freely in space; not strongly bilaterally symmetric; tubular and hard-textured; vivid colours (often including orange or red or other colours with stark contrasts); no scent; abundant nectar in relatively short and broad receptacles; nectar guide absent. Probably at least a hundred species are ornithophilous (pollinated by birds), including all species of the genera Mediocalcar and Epiblastus, and in addition many species of Glomera and Dendrobium, as well as a few species of Calanthe (Schuiteman 1997). Most of these occur in mountain habitats that are generally cool and cloudy, with relatively few insects.

Insect pollination is probably frequent, although very few observations have been recorded. Some species of Bulbophyllum have really bizarre flowers, e.g. B. cimicinum J.J.Verm. of the section Epicrianthes. This species has a structure in the flower which is the most arthropod-like imitation ever recorded for an orchid, as far as we know. The sepals are unremarkable, but the petals and the lip have a shape resembling a little spider. The two petals each carry four black, hairy, leg-like appendages which wriggle in the lightest breeze. It seems unlikely that this Bulbophyllum is aiming to lure other spiders, as these are bound to be very inefficient pollinators. One possibility we can think of is that the orchid mimics a prey to attract spider-catching insects. Related species are also bizarre, and show a variety of shorter or longer threat-like appendages, either or not beset with hairs, or even swollen balloons ending in a slender point, with hairs or papillae, sometimes combined with large projecting hyaline cells on the lip. These features must all have a function the pollination mechanism, although no records exist that this has actually been observed.

The project: “Flora Malesiana. Orchids of New Guinea on CD-ROM”

The National Herbarium Nederland is engaged in a project: “Flora Malesiana. Orchids of New Guinea on CD-ROM”. This project aims at producing a synopsis of all current knowledge on the orchids of New Guinea. This is included in an information retrieval system named Linnaeus II, designed by ETI (Expert Centre for Taxonomic Identification) on request of UNESCO. This can store large amounts of biological information. ETI published already some 80 CD-ROM’s on a wide selection of topics in the series World Biodiversity Databases, including Lobsters of the World, Sea Cucumbers of Australia, and the Flora of the Netherlands, to name a few. Already 3 orchid CD-ROM’s have been published in the Flora Malesiana series. One is Orchids of the Philippines, vol. I: Illustrated Checklist and Genera (Agoo, E. M.G., Schuiteman, A. & E.F. de Vogel 2003). For New Guinea a series of 6 CD-ROM’s is planned, to be finished end 2005, of which two have already been published: Orchids of New Guinea, vol. I: Illustrated Checklist and Genera (Schuiteman, A. & E.F. de Vogel. 2002) and vol. II: Dendrobium and allied genera (Schuiteman, A. & E.F. de Vogel. 2002). A third will be available in April 2005: Vol. III: The genera Acanthephippium to Hymenorchis (excluding Bulbophyllinae and Dendrobiinae). In 2005, the texts for the remaining 3 CD-ROM’s will be produced, and the complete New Guinea Orchid Flora will be available halfway 2006!

These orchid publications are made in close co-operation with major Botanical Institutes in Papua New Guinea, the Philippines, Indonesia, Vietnam, England, and Denmark, as part of a much larger project: Orchids of Southeast Asia on CD-ROM which aims at publishing all 8000 described species.

The CD-ROM’s contain for each taxon a combination of the following data: the accepted name and synonyms, literature references, a description, its distribution, drawings and photographs, information on and photographs of types, notes on cultivation, etc. Identification keys are present, as well as hyperlinked glossary, linked to all texts. These CD-ROM’s are the only modern and up to date information source on New Guinea orchids, and all species have a description in English.

Present exploration activities

To increase the knowledge of New Guinea orchids, a series of several exploration and inventory trips are scheduled in the period 2003-2008, organised by the National Capital Botanic Gardens in Port Moresby and the Nationaal Herbarium Nederland, Leiden Branch, with support of the PNG Department of Environment and Conservation. On these trips live orchids will be collected and grown in botanic gardens in PNG and The Netherlands. Aim is to identify, document, preserve and photograph these orchids when flowering, in order to gather valuable information to enhance future CD-ROM’s and to enhance knowledge on distribution and species richness. Two field inventories have thus far been made in 2003, resulting each in c. 1000 live orchid collections. Although so far only some 500 plants have flowered, the results are amazing. More than 40 species new to science have already been discovered, and these are now in the process of being described. Extensions of distribution ranges have been established for many species. The most striking example is a second collection of Cleisostoma buruense J.J.Sm., first record for New Guinea and 2500 km from the type locality in the Moluccas. Many more exciting finds are anticipated when more areas are visited and more plants come into flower. The CD-ROM series will highlight this unique orchid flora and give an account which is of much interest to scientists, horticulturists, conservationists, ecologists and orchid amateurs alike!

Flora Malesiana: Orchids of New Guinea Vol. III
Genera Acanthephippium to Hymenorchis (excluding Bulbophyllinae &Dendrobiinae)

This CD-ROM reflects the state of the art in our expertise of the incredibly rich orchid flora of New Guinea, pertaining to 60 genera (Acanthephippium to Hymenorchis) with nearly 600 species. Important genera include Calanthe, Coelogyne, Corybas, Eria, and Glomera. Not treated here are the genera Dendrobium and Bulbophyllum with their allies, as these are the subjects of separate volumes in this series (vol. II and VI respectively). For every species a full description is given, with data on distribution (including maps), synonymy, cultivation, ecology, typification, classification, etc. An impressive collection of colour photographs and drawings, both published and unpublished, adds to the exceptional value of this CD-ROM. Several leading botanical institutes, such as the Royal Botanic Gardens, Kew, the Royal Botanic Garden, Edinburgh, the Herbarium Bogoriense, Bogor, and the National Capital Botanic Garden, Port Moresby, as well as many well-known photographers have contributed to this CD-ROM, which is a must for all who are interested in the orchids of New Guinea and Southeast Asia.

In the same series these CDs have been published: