Trees of Papua New Guinea: Volume 1: Introduction and Gnetales to Fabales

By Barry J Conn and Kipiro Q Damas

The island of New Guinea has a high diversity of species and a high level of endemism, containing more than 5 percent of earth’s biodiversity in just over one half of a percent of the land on the earth. New Guinea supports the largest area of mature tropical moist forest in the Asia/Pacific region. Papua New Guinea consists of the eastern part of the island of New Guinea, plus the islands of the Bismarck Archipelago, Buka, and Bougainville. There are between fifteen thousand and twenty thousand species of vascular plants in Papua New Guinea, with at least two thousand species of trees. The most important challenge for Papua New Guinea is the protection of biological diversity against the pressures resulting from global climate change, inappropriate destructive conversion of natural communities, unsustainable exploitation of forests, national economic development and societal demands, including a fair sharing of the nation’s wealth, and law and order issues.

There are very few resources available to natural resource managers, environmental scientists, nongovernment agencies, and various extractive industries, most importantly, the timber industry that will assist in the identification of major tree species within Papua New Guinea. It is hoped that the publication of these three volumes will enable those who are responsible for natural resource management to improve their knowledge of the trees in these forests so that they can fully appreciate the richness of these biologically diverse forests. The forests of Papua New Guinea need to be managed sensitively and sustainably based on advanced evidence-based knowledge.

The Trees of Papua New Guinea publication provides a comprehensive treatment of 668 species of trees (Volume 1: 257 species; Vol. 2: 246 species; Vol. 3: 165 species) that will assist in the identification of the trees of Papua New Guinea.

• Language: English
• Publisher: Xlibris AU
• Release date: Apr 10, 2019
• ISBN: 9781984505064

Barry J Conn

Barry J Conn: Principal Research Scientist (National Herbarium of New South Wales, Sydney, Australia) and Associate Professor (The University of Sydney). He specialised in the systematics of the floras of Malesia, Australasia and Pacific Islands, with special focus on the systematics of the trees of New Guinea and several other plant families. He was employed as a botanist at the Papua New Guinea National Herbarium (Lae) and as a lecturer at the Bulolo Forestry College (1974 -1979). Since 1982, he regularly visited PNG to continue his botanical research and to document and describe trees for the PNGtrees project. Kipiro Q. Damas: Graduated with a Diploma in Forestry from the Papua New Guinea Forestry College, Bulolo in 1978. Employed as an Assistant Botanist at the Papua New Guinea National Herbarium (Lae) while completing a Bachelor of Forestry Science, PNG University of Technology, in 1992. Continued as a Botanist at the Lae Herbarium. In 2009 he graduated with a Bachelor of Honours from the University of Papua New Guinea and continued to work as the Senior Botanist at Lae. Recently completed his studies for a Master of Science degree at the University of Papua New Guinea.

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Copyright © 2019 by Barry J Conn and Kipiro Q Damas. 764713

ISBN:    Softcover   978-1-9845-0507-1

   Hardcover   978-1-9845-0508-8

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Rev. date: 04/08/2019

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Trees of Papua New Guinea

Volume 1

Introduction and Gnetales to Fabales

by

Barry J Conn and Kipiro Q Damas

A collaborative project of the Royal Botanic Gardens,

Sydney, Australia and the Papua New Guinea Forest

Research Institute, Lae, Papua New Guinea

53893.png

Contents

Introduction

Key morphological features for selected tree families, genera and species

Taxonomic Treatment

Pinophyta

Gnetales

1. Gnetaceae

Gnetum

2. Araucariaceae

Agathis

Araucaria

3. Cupressaceae

Papuacedrus

4. Pinaceae

Pinus

5. Podocarpaceae

Dacrycarpus

Dacrydium

Falcatifolium

Nageia

Phyllocladus

Podocarpus

Prumnopitys

Retrophyllum

Magnoliophyta Class Magnoliopsida (Dicotyledons)

Chloranthales

6. Chloranthaceae

Ascarina

Magnoliales

7. Myristicaceae

Endocomia

Gymnacranthera

Horsfieldia

Myristica

8. Magnoliaceae

Magnolia

9. Himantandraceae

Galbulimima

10. Annonaceae

Cananga

Cyathocalyx

Goniothalamus

Polyalthia

Popowia

Xylopia

Laurales

11. Monimiaceae

Levieria

Steganthera

12. Hernandiaceae

Hernandia

13. Lauraceae

Actinodaphne

Alseodaphne

Beilschmiedia

Cinnamomum

Cryptocarya

Endiandra

Litsea

Phoebe

14. Atherospermataceae

Dryadodaphne

Canellales

15. Winteraceae

Zygogynum

Proteales

16. Proteaceae

Banksia

Finschia

Grevillea

Helicia

Stenocarpus

17. Sabiaceae

Meliosma

Dilleniales

18. Dilleniaceae

Dillenia

Saxifragales

19. Daphniphyllaceae

Daphniphyllum

Celastrales

20. Celastraceae

Bhesa

Lophopetalum

Siphonodon

Oxalidales

21. Cunoniaceae

Caldcluvia

Ceratopetalum

Pullea

Schizomeria

Weinmannia

22. Elaeocarpaceae

Aceratium

Dubouzetia

Elaeocarpus

Sericolea

Sloanea

Malpighiales

23. Erythroxylaceae

Erythroxylum

24. Rhizophoraceae

Bruguiera

Carallia

Ceriops

Gynotroches

Rhizophora

25. Pandaceae

Galearia

26. Ochnaceae

Brackenridgea

Schuurmansia

27. Clusiaceae

Garcinia

28. Calophyllaceae

Calophyllum

Kayea

29. Putranjivaceae

Drypetes

30. Chrysobalanaceae

Atuna

Maranthes

Parastemon

Parinari

31. Achariaceae

Erythrospermum

Pangium

Ryparosa

Trichadenia

32. Salicaceae

Casearia

Flacourtia

Homalium

Itoa

33. Euphorbiaceae

Aleurites

Annesijoa

Blumeodendron

Claoxylon

Croton

Endospermum

Excoecaria

Macaranga

Mallotus

Pimelodendron

34. Phyllanthaceae

Antidesma

Bischofia

Bridelia

Cleistanthus

Glochidion

Fabales

35. Fabaceae

Subfamily Faboideae

Castanospermum

Erythrina

Inocarpus

Ormosia

Pongamia

Pterocarpus

Subfamily Caesalpinioideae

Crudia

Gigasiphon

Intsia

Kingiodendron

Maniltoa

Subfamily Mimosoideae

Acacia

Adenanthera

Albizia

Paraserianthes

Serianthes

36. Polygalaceae

Eriandra

Xanthophyllum

REFERENCES (Volume 1)

Introduction

1PNGmapgeneral.psd

Map showing Papua New Guinea (coloured in green), eastern Indonesia and northern Australia. © Map by freevectormaps.com, modified by Alan Wallace (Yarrawonga, Victoria)

The island of New Guinea is a region that has a high diversity of species and a high level of endemism, containing more than 5% of earth’s biodiversity in just over one half of a percent of the land on the earth (Mack 1998). It is a region that is rich in biodiversity, geomorphology, peoples, languages, history, traditions and culture (Gressitt 1982).

New Guinea supports the largest area of mature tropical moist forest in the Asia/Pacific region. Papua New Guinea consists of the eastern part of the island of New Guinea, plus the islands of the Bismarck Archipelago, Buka and Bougainville. There are between 15,000 and 20,000 species of vascular plants in Papua New Guinea (Johns 1993), with the number of non-vascular plants between 2,000 and 2,500 species (based on work by Grolle and Piippo 1984, Piippo and Koponen 2003, and papers cited therein, Miller et al. 1985). Unfortunately, this very rich flora is threatened by many recent and serious environmental changes. The loss of biological resources in Papua New Guinea is driven primarily by non-biological factors (Swartzendruber 1993) and the country’s ecosystems are being degraded at an alarming rate (Sekhran and Miller 1995, Shearman et al. 2009). The most important challenge for Papua New Guinea is the protection of biological diversity against the pressures resulting from global climate change, inappropriate destructive conversion of natural communities, unsustainable exploitation of forests, national economic development and societal demands, including a fair sharing of the nation’s wealth, and law and order issues.

Although the Papua New Guinean land tenure laws and traditions help to ensure that the indigenous people’s land rights are secure from excessive commercial interests, large areas of forest are being destructively harvested contrary to the long-term welfare of the people. The country’s forest industry is predominately focused on the harvesting of natural forest areas for round log export. There is little plantation production and only a limited number of processing facilities (ForestTrends 2006). Governments and the large logging companies that dominate the timber industry in Papua New Guinea need to find a sustainable way of using the timber resources of forests that is sympathetic to the importance of these ancient forests as habitat for countless species and as the home for the indigenous people of Papua New Guinea. Destructively and illegally extracted timber exacts a disastrous toll on forest eco-systems and on the lives of forest-dwelling peoples (Greenpeace 2004). This latter report also concludes that such unsustainable activities deprive developing countries of revenue and resources necessary for survival and national development. The immediate impact of excessive de-forestation all too often results in people suffering from human rights abuses, great poverty, disease and other social problems as forests are destroyed (Chesterfield 2006, Greenpeace 2004).

The possibility of illegal logging in Papua New Guinea should be minimal because almost all timber harvested from natural forests is officially approved by the issue of a permit or license. However, although all timber harvesting may be officially licensed, there are serious issues of legal non-compliance at almost every stage in the development and management of these projects (ForestTrends 2006). This latter study concluded that current commercial forest management is ecologically and economically unsustainable and illegal, with logging not serving the long-term interests of landowners or the nation (ForestTrends 2006). The current lack of long-lasting conservation actions on the scale necessary to arrest this trend is of concern because the rich ecosystems of Papua New Guinea supply essential goods and services that underpin the nation’s primary resource-based economy (Sekhran in Sekhran and Miller 1995). Although the Papua New Guinean land tenure laws and traditions make it more difficult to exploit natural resources, these same laws and traditions tend to hinder the long-term establishment of large conservation areas to protect biodiversity from the rapid degradation observed in some areas. Population growth further erodes biodiversity as traditional cultural values are replaced by more Western-style living expectations. The subsequent reduction in biodiversity leads to a devaluing of the remaining resources, which further fuels an increased rate of habitat conversion by people (Gumoi and Sekhran in Sekhran and Miller 1995). All too frequently, the current economic model used by exploitative developers implicitly assumes that the economic value of short-term exploitation of natural resources exceeds long-term conservation values (Sekhran in Sekhran and Miller 1995). The loss of these natural resources results in excessively high welfare costs for future generations. Foreign governments will have to assist Papua New Guinea to meet the costs of conservation intervention as part of the global strategies needed to combat anthropogenic changes to climate (as defined by ‘The United Nations Framework Convention on Climate Change’, UNFCCC 1992), with mandatory emission limits established in the ‘Kyoto Protocol’ (1997, ratified June 2007). It was hoped that Papua New Guinea would be able to conserve large traits of forest by receiving financial compensation through a global carbon emission trading (‘carbon credits’) strategy. It is very clear that we already have too much carbon in the air for climate stability. With extensive forested areas, Papua New Guinea is in an ideal position to use these forests to store high levels of carbon in plants and the soil. It is thought that enough carbon can be stored in the living biosphere, particularly in the tropics, to offset all of the carbon emissions since the beginning of the industrial revolution (Sara 2007). Therefore, there is a significant opportunity for Papua New Guinea to use a more balanced, long-term economic model for assessing the financial value of their natural resources, compared to short-term commercial value, than is currently being applied.

Documentation of the flora of Papua New Guinea

In February 1998, The Darwin Declaration began by stating that:

"The governments of the world that recognise the Convention on Biological Diversity have affirmed the existence of a taxonomic impediment to sound management and conservation of biodiversity. Removal of this impediment is a crucial, rate-determining step in the proper implementation of the Convention’s objectives. There is an urgent need to train and support more taxonomic experts, and to strengthen the infrastructure required to discover and understand the relationships among the world’s biological diversity." (ABRS 1998).

Taxonomy is the science of discovering, describing and naming the individual species of plants and animals, and of revealing their relationships to provide a classification. Taxonomy provides the reference system for all organisms, and the framework on which the skills to identify and specify the elements of biodiversity are based (ABRS 1998). Biodiversity can only be understood within a sound taxonomic framework.

"Conference of [the] Parties [to the Convention of Biodiversity¹] stresses the urgent need for adequate financial resources to implement a Global Taxonomy Initiative and requests the institutional structure of the financial mechanism of the Convention to provide financial resources, particularly to assist in implementing, through country-driven activities …" (ABRS 1998).

Although, globally, there is strong political agreement about the importance of remedying the crisis resulting from the taxonomic impediment, limited financial opportunities have been available for developing a framework in which the documentation of the flora of Papua New Guinea can be developed and maintained by within-country taxonomists. A detailed summary of botanical research in Papuasia (which includes Papua New Guinea) is provided by Frodin (1990). The documentation of the flora of Papua New Guinea still relies heavily on the research efforts of scientists who are working outside of the country (Conn 1994). It is disappointing that major research initiatives on the flora of New Guinea (Papua New Guinea and Indonesian Papua) are still being developed and undertaken by external researchers without consideration or involvement of within-region scientists. However, even with many world experts studying the systematics of this region’s flora, the documentation of these vascular plants remains very incomplete. Furthermore, these descriptions of the plants of Papua New Guinea are scattered throughout various scientific publications, many of which are not readily available within the country. Even the collaborative efforts of the Biodiversity Heritage Library initiative (BHL 2008+) to make biodiversity literature openly available via the internet has had limited success within Papua New Guinea. Most Papua New Guineans do not have access to the internet, or when available, it is most frequently unreliable, slow and/or very limited. The status of many of the published species concepts has not been tested by subsequent field studies nor evaluated by the normal scientific review process by Papua New Guinean scientists. However, there have been many major contributions to our understanding of the flora of this region published in a considerable number of international research journals and books. Significant contributions to our understanding of the flora of this region have been provided by the scholarly accounts in the Flora Malesiana series (for details refer to Anonymous 2014 onwards), the Alpine flora of New Guinea (Royen 1979–1983) and the three volumes of Handbooks of the flora of Papua New Guinea (Conn 1995, Henty 1981, Womersley 1978). Other miscellaneous publications include the Manual of the forest trees of Papua New Guinea series (Balgooy 1997, 1998, Coode 1969, Peekel 1984, Royen 1964a, b, c, [1965]-a, b, c, [received 2 December 1966]); Malesian seed plants (Balgooy 1997, 1998) and Flora of the Bismarck Archipelago (Peekel 1984). However, the expectation that the LAE herbarium would produce a local flora of the region (Womersley and McAdam 1957) has not eventuated. To evaluate the taxonomic concepts presented in these publications, continual field-based review is required so that the complex plant diversity of Papua New Guinea is fully understood and interpreted. However, there are almost no publications on this flora by Papua New Guinea botanists (Banka and Baker 2004, Banka and Barfod 2004, Barfod et al. 2001, Conn and Damas 2010, 2013, Conn and Kerenga 1995, Paul 2013). Few indigenous botanists have the necessary experience to complete the documentation of the flora (Conn 1994) and most do not get an opportunity to develop these expertise. However, there are many publications by within-country botanists on other important aspects of the flora (for example: Barrows et al. 2009, Galegau et al. 1985, Holdsworth et al. 1989, Holdsworth and Kerenga 1987, Holdsworth and Wamoi 1982, Kerenga and Croft 1985, Nora et al. 2008, Sitapai et al. 1999). Under-graduate and post-graduate training in basic botany and plant identification are limited, frequently based on old texts and manuals (Conn 1978, 1979, Havel 1975, Hay 1981, 1984a, b, Howcroft 1984, Johns 1975–1976, 1988a, b, 1989, Johns and Bellamy 1979, 1981). Furthermore, instruction in advanced plant systematics has probably never been implicitly taught at tertiary levels within Papua New Guinea.

The PNGtrees project – the electronic version

The publication of this three volume guide to the ‘Trees of Papua New Guinea’ is based on an online collaborative research program (the PNGtrees project) between the National Herbarium of New South Wales (NSW) and the Papua New Guinea National Herbarium (LAE). It was recognised that one of the major concerns facing the people of Papua New Guinea is their capacity to document the rich biodiversity of their country. The aim of the project, began in March 2003, was to develop a simple, structured method for documenting the flora of Papua New Guinea, with the first phase focusing on the economically important and common tree species. The guiding principle was that this project should not only document the tree flora of this nation, but it should train future indigenous scientists to be experts on the taxonomy of the flora of Papua New Guinea. If the resources available to these scientists were likely to remain limited, at least in the short- to medium-term, then the documentation process of the PNGtrees project had to be achieved with minimal technical support and with few personnel. Since the Papua New Guinea National Herbarium (LAE) has limited computational capability, the system needed to be simple, being both easy to operate and manage, without compromising the quality of the data.

There are very few resources available to natural resource managers, environmental scientists, non-government agencies, and various extractive industries, most importantly, the timber industry, that will assist in the identification of major tree species within Papua New Guinea. The unnecessary destruction of rare and otherwise valuable tree species has, in part, resulted from the inability to distinguish these species from the preferred timber species. Furthermore, the mixture of unwanted timber with that from preferred species has frequently resulted in the downgrading of all timber to wood-chip. The plant identification tools presented in the electronic version of PNGtrees (together with the descriptions, diagrams, botanical illustrations and images), assists users to identify the major trees of the region using simplified terminology. It is hoped that the PNGtrees project enables those who are responsible for natural resource management to improve their knowledge of the trees in these forests so that they can fully appreciate the richness of these biologically diverse forests.

Details of the electronic version of the PNGtrees project

The electronic version of the PNGtrees project was designed to be an internet-based documentation process that can be maintained, via the internet, such that current information can always be accessed by users. Since this is a long-term project, it is expected that additional species will be added to the ‘Guide to trees of Papua New Guinea’ and the available information will be regularly verified, corrected and expanded. The descriptive data used to document the diagnostic morphological features of the trees of Papua New Guinea are managed in a database. The development of the descriptive data set was based on the work of several previous projects so that there was some commonality in these data and that used in the PNGtrees project. In particular, the data dictionary (glossary of terms) used was based on those used in Australian tropical rain forest trees (Hyland et al. 1993), the tree and shrub genera of Borneo (Jarvie and Ermayanti 1995–1996), trees of Borneo (Webb et al. 2005, Webb et al. 2008+), the flowering plants of Australia (Thiele and Adams 1999), and the Western Australian Flora (FloraBase 2003). Initially, the development of the data dictionary for the PNGtrees project was based on the recognised commercial trees of Papua New Guinea (Eddowes 1977).

Software Tools:

Descriptive taxonomic information is best done within a framework of integrated databases, combining raw observational or experimental data, and reviewed or summarised data with nomenclatorial, literature references and specimen collection database subsystems (Hagedorn 1999). The DiversityDescriptions (version 2.0 beta 12) software, previously DeltaAccess (version 1.9) software (Hagedorn 1999, 2006) has been used to manage the data because it is freely available and is based on the readily available Microsoft® Office Access® database software. DiversityDescriptions also enables the definition of plant features and other important characteristics to be managed by the software, such that it acts as a controlled vocabulary. Furthermore, DiversityDescriptions is able to output these data in DELTA format (Dallwitz 1993, 2005, Dallwitz et al. 1993+) which makes these descriptive data widely available for other applications. The DELTA format has been adopted by the International Taxonomic Database Working Group (TDWG 2006) as a standard for data exchange.

The descriptions of the trees included in the electronic version of PNGtrees have been generated by DiversityDescriptions software. The presentation of these data was further manipulated for publication in the PNGplants website (Conn et al. 2006+) using automated Perl scripting (Anonymous 2007). The generation of distribution maps from the PNGplants collections database (Conn et al. 2004+) were also automated using Perl scripts (Anonymous 2007) The PNGplants database uses KE Texpress software, a single-table object-orientated UNIX database (Anonymous 2006). The web-based data sheets used to score the descriptive morphological features are managed by DiversityDescriptions. The data are exported from the PNGtrees database as DELTA-formatted files. These DELTA files can be imported into software that can generate interactive (electronic) identification tools. The NaviKey (version 4.09) interactive identification software (Neubacher and Rambold 2005 onwards) has been used because it is open-source developed software that is readily available.

The scientific plant names, including plant family names, used in PNGtrees are based on listings in International Plant Names Index (IPNI 2004+) and the Angiosperm Phylogeny Website (APG 2016 onwards, Stevens 2001 onwards). These names form the basis of PNGCensus (Conn 2008+) and are managed in KE EMu software database (Anonymous 1998–2005). Vernacular plant names are based on commonly accepted English and/or trade names (Eddowes 1977). Tokples names have not been provided because the collation of all reported vernacular names is beyond the scope of this project.

This book has been written for field anthropologists, botanists, ecologists, environmentalists and others requiring knowledge of the trees of Papua New Guinea. For this reason, botanical terminology has been kept as simple as possible and images are presented as often as possible to assist with identification. However, it must be realised that although much is known about the tree flora of Papua New Guinea, there are many putatively undescribed taxa which are currently included within other broadly defined species. Furthermore, the morphological variation within many species is inadequately known. Therefore, the distinction between species is often difficult. Furthermore, except for a few, the distribution of most species is very inadequately known.

Sequence of Descriptions

The descriptions of the trees dealt with in this book are arranged according to the orders and families recognised by Stevens (2001 onwards). This system is based on recent phylogenetic concepts developed from a wide-range of data, but particularly from molecular sequence data. Although our knowledge of the major groupings of seed plants and the relationships both within and between them are still undergoing revision as new data are evaluated, much of the broad structure is well understood (APG 1998, 2003, 2009, 2016 onwards). This new classification differs significantly from older systems such as that of Cronquist (1981), as used by Höft (1992). Therefore, users may be unfamiliar with some family concepts and even uncertain of the generic composition of several previously well-known families.

Arrangement of book

Although the families are arranged according to their placement within Orders as defined by Stevens (2001 onwards), the genera and species within these are arranged alphabetically. Within each Order, a key to all families or, at least to those treated in this book, is provided. The conifers (Pinophyta) are treated before the dicotyledons (Class Magnoliopsida, Magnoliophyta). Within each family, a key to subfamilies (when recognised) and genera that occur in Papua New Guinea, or at least to those treated here, is provided to assist with identification.

Identification of trees

When using this book to identify a tree, the following points should be considered:

• Although the technical terms used in this ‘Guide’ have been minimised (for details refer to the Data Dictionary, Volume 3), the definition of these, together with the non-technical terms, must be fully understood. We have tried to use all technical terms in a way that is consistent with general usage and non-technical terms in a way that we believe is readily understood; however, this usage may differ from your understanding of these terms. There are many excellent references providing definitions of technical botanical terms and a search of the internet will recover several excellent online glossaries (for example: Flora of China undated, Lynne undated, Radford et al. 1998). However, it is preferable to use the glossary of terms provided in this publication for identification purposes. Some otherwise ‘standard’ terms may be defined slightly differently in various botanical publications.

• A tree is defined as a single stemmed woody plant. Most trees included in this ‘Guide’ are at least 20 m high and at least 20 cm diameter. Some trees of smaller stature have been included so that a greater range of plant families can be represented.

• When comparing leaf features of the tree with the descriptions, it is important to determine correctly whether the leaves are simple or compound. If it is incorrectly assumed that the leaves are simple, when they are compound, then the presence or absence of stipules and arrangement of leaves will almost certainly also be incorrect.

• When examining the inner and outer bark features, be careful not to damage the cambial layer or sapwood when making the blaze. If the tree has buttresses, then the blaze should not be made on or near the ridges of buttresses. The blaze should be as far removed from buttresses as possible as this will result in more consistent and more definite blaze colours.

• In general, features of flowers and fruits are more reliable for identification purposes than leaf features, with bark and habit features tending to be the least reliable. However, habit, bark and leaves features are readily available, whereas flowers and fruits are frequently either not present or are inaccessible.

• Identification keys are only provided to higher level groupings of trees, for example, to families, subfamilies, genera and sometimes to lower level groupings, such as subspecies and varieties. If you know which family the tree belongs to, then this information can be used to assist in the identification of the tree species. Naturally, the use of family names requires some additional previous botanical knowledge. It is important to be aware of the current realignment of many genera and species to different families based on the results of molecular evidence. Therefore, the concepts of many families have changed considerably in recent years. It was not feasible to include all of the detailed morphological features that would be required to completely identify all trees. Furthermore, it has not been possible to include all the morphological variation that may be present in a species. Sometimes the less common morphological states have not been included intentionally because they are rarely encountered. In other examples, the full extent of the morphological variation is not known for species that are not taxonomically well-defined.

• Even if the tree has been fully identified using this ‘Guide’, it is recommended that verification of the identity should be made by comparing a botanical collection of the species with herbarium material held at the Papua New Guinea National Herbarium, PO Box 314, Lae, Papua New Guinea. References on how to make botanical collections suitable for identification purposes include: Conn (2011), Fish (1999), Forman and Bridson (1989), Victor et al. (2004), Womersley (1969, 1976).

Background to the publication of this book

The accounts of the species, subspecies, varieties and forms include the following information:

Plant name

Accepted scientific name

Authority – author(s) of scientific name

place of original publication, including volume, page number(s), figures and year of publication

Group name

Vernacular name – general name used for a group of trees, for example, Mangrove

Timber group – whether or not it is used for timber and if so, then what type of timber species it is

Trade name – as used in the forestry and timber industries

Morphological features

The morphological features used in the descriptions in this book include the following:

General (field) features – habit, trunk features, bark, exudate and indumentum (types of hairs) on branches;

Leaf – general leaf features, including leaf position, arrangement on branchlets, petiole features, colour, indumentum; and more specific features, such as, lamina shape for simple leaves or compound leaflets, size, lamina colour, base, margin and apex features, venation, domatia and stipules;

Flower – arrangement, presence of cones/strobili (for conifers), flower sexuality, size and symmetry; perianth features; staminal (stamens) characteristics; and features of the gynoecium (including ovary and style);

Fruit (for dicotyledons) – arrangement, size, colour, surface, texture, structure, whether dehiscent or indehiscent;

Cone (for conifers) – presence, size and colour;

Seed – number, size, shape, presence of wings.

The distribution of the species within Papua New Guinea is summarised according to botanical regions, as defined by Conn (1995). A distribution map is provided together with point data (red dots) from the vouchered collections in the PNGplants database (Conn et al. 2004+). The distribution of cultivated or possibly cultivated trees are represented by black dots. Plant collections from near the boundary of provinces frequently plot slightly outside the correct province. These mapping errors are the result of inaccurate geocodes provided by the collector; geocodes that cannot be corrected because of imprecise locality information. In other instances, the geocode provided is not sufficiently precise for the scale of the maps being used here.

Supplementary images and additional notes are frequently provided.

Key morphological features for selected tree families, genera and species

The following diagnostic characters (spot-characters) are provided to assist in the identification of the more distinctive tree species. The spot-characters that are constant for the plant family or genera are listed. Important characters are emphasized in bold.

Notes: There are many useful publications that can assist with the identification of trees in Papua New Guinea; however, two books that provide spot-characters for trees of the Malesian region (Balgooy 1997, 1998) are recommended. Although the taxonomy used in Havel (1975) is no longer current, this is a very useful guide to the important diagnostic features of trees of Papua New Guinea.

GNETUM

GNETACEAE

Trees, shrubs, often climbers; outer bark smooth, except for a regular set of raised rings; small branchlets with swollen nodes; leaves simple, opposite, often with translucent lines, with margin entire; venation pinnate; stipules absent; bracts absent; uniflorescence a spike; flowers unisexual (plant dioecious), with inner and outer tepals 1 or 2; stamens 1 (in male flowers); fruit simple, indehiscent, drupe, slightly fleshy. Seeds 1, without wings

Gnetum is the only genus in this family.

CONIFERS

ARAUCARIACEAE

Large canopy and emergent trees, without buttresses; bark thick, rough, with exudate resinous; leaves spiral, tough, leathery; venation parallel; male flowers consisting of scales and anthers only, arranged in cylindrical compact spikes on lower branches; female flowers consisting of scales and ovules only, arranged in short spikes on top branches; fruits compound (cone)

CUPRESSACEAE

Trees and shrubs; stipules absent; leaves much reduced, flattened, scale-like, opposite, simple, with margin entire; venation parallel. Inflorescences terminal (male flowers on short shoots; female cones); bracts present, as scales of female cones; flowers unisexual (then plant dioecious), regular, perianth reduced to scales. Stamens 2, free; filaments absent; cones woody to leathery; seeds with wings.

PINACEAE

Trees (introduced as plantation species); stipules absent; leaves much reduced, needle-like, grouped in clusters (in Pinus), whorled, simple, with margin entire; venation parallel. Inflorescences axillary (pollen cones) or terminal (female flowers on short scaly shoots, forming more or less cylindrical cones); bracts present; flowers unisexual (then plant monoecious), zygomorphic or slightly irregular, perianth absent. Stamens (microsporophylls) scale-like, 1 (consisting of 2 inverted pollen sacs), free; filaments absent. Gynoecium consisting of one carpel, superior, with 2 inverted ovules on each scale; styles absent. Cones present; scales becoming woody. Seeds egg-shaped, with an expanded wing attached to their base.

PODOCARPACEAE

Trees and shrubs; stipules absent; leaves much reduced, scale-like, needle-like, or flattened or well-developed, spiral or opposite, simple, with margin entire; venation parallel or reduced to 1-nerved (mid-vein). Inflorescences (pollen cones and female seed-bearing structure) axillary; bracts present, joining to forming a receptacle (female cone not present). Flowers unisexual (then plant usually dioecious), slightly irregular, perianth absent. Stamens 15, usually winged, free; filaments present. Gynoecium consisting of one inverted ovule on a naked peduncle, superior; styles absent. Cones absent; female receptacle usually becoming slightly fleshy; seeds covered by leathery tissues.

Adult leaves suppressed

Leaves dimorphic (of two types)

Leaves bilaterally flattened

Falcatifolium papuanum

Leaves bifacially flattened

FLOWERING PLANTS

ACANTHACEAE

Trees (e.g. Avicennia – mangroves), shrubs or herbs; leaves with margin entire or toothed; stipules absent; corolla lobes narrow; stamens 2 (with or without 2 staminodes) or 5.

ACTINIDIACEAE

Small to subcanopy trees, or shrub; leaves spiral, simple, with margin toothed; stipules absent. Flowers regular, 5-partite; petals joined at base; stamens many; fruit a berry.

ANACARDIACEAE

Small to large trees; leaves simple or compound; stipules absent. Bark with exudate turning black or brown when exposed (slashed).

Notes: Several species have exudate which may cause severe and painful irritation to the skin.

Simple leaf genera

Compound leaf genera

ANNONACEAE

Small to large trees; bark fibrous; leaves simple, arranged in two opposite rows, with margin entire; stipules absent. Usually with flowers of 3- or 6-partite, stamens many

APOCYNACEAE

Small to large trees (also shrubs, climbers and herbs), with flowing milky exudates on exposure (slash bark etc.); leaves simple with margin entire. Flowers 4- or 5-partite; corolla lobes contorted (one lobe partly covered by the next lobe) in bud; stamens 5. Usually with leaves opposite; stipules absent but sometimes with ridge between each pair of leaves.

AQUIFOLIACEAE

Small to large trees; stipules present; leaves spiral, opposite, or whorled, simple, dissected, lobed, or margin entire; venation pinnate. Inflorescences axillary; Flowers unisexual (then plant dioecious), regular, with distinct calyx and corolla. Sepals 4–8. Petals 4–8, joined, at least in part; tube present. Stamens 4–8, free; filaments present; staminodes present in female flowers; fruit simple, indehiscent, drupe or berry, fleshy. Seeds without wings. In Papua New Guinea, only Ilex.

ARALIACEAE

Small to large trees, also shrubs, with stems resinous, with thick pith; leaves spiral; ultimate branch of inflorescence clustered in an umbel; sepals absent or small; petals free, soon deciduous; fruit a drupe. Usually plants aromatic, petiole with ligule, leaves compound and inflorescence terminal.

ASTERACEAE

Shrubs or herbs, (in Papua New Guinea, only one tree species – Vernonia arborea); stipules absent. Flowers (florets) sessile, arranged on a receptacle which is usually flat, forming a head, regular or zygomorphic, usually bisexual or female; petals usually 5 (sometimes 4), surrounded by scales, hairs, bristles or awns; stamens usually 5, united by their anthers to form a tube around the style. Fruit usually dry, indehiscent, cypsela.

ATHEROSPERMATACEAE

Medium to large trees; leaves opposite or sub-opposite, with margin coarsely and irregularly toothed; lateral veins joined to form a looping vein near margin; stipules absent; flowers medium in size; individual fruitlets plumose and achene-like – in Papua New Guinea, only Dryadodaphne.

BIGNONIACEAE

Trees, shrubs, lianas, and rarely herbs; leaves usually opposite or whorled, usually compound, bipinnate, pinnate, or palmate; stipules absent; flowers usually large and showy, bisexual, zygomorphic or slightly irregular; sepals and petals 5; fruit simple, usually a dehiscent capsule; seeds usually with wings.

Only the canopy tree Lamiodendron magnificum treated here.

BORAGINACEAE

Trees, shrubs, lianas, and herbs; leaves spiral or opposite, simple, with margin entire; venation pinnate or palmate (3-veined at base); stipules absent; flowers bisexual, slightly zygomorphic; sepals usually 5–8; petals and stamens 5; fruit simple, dehiscent or indehiscent, drupe, with 1–4 seeds, without wings.

BURSERACEAE

Medium to large trees, or shrubs. Bark blaze with distinct odour; leaves spiral, compound, pinnate, unifoliate, or trifoliate, with margin entire; seeds without wings.

CALOPHYLLACEAE

Small to large trees and shrubs; bark sometimes with soft bristles and fibrous; stipules absent (by misinterpretation), present as stipular glands; leaves opposite or subopposite, simple, with margin entire; venation pinnate, with veins close together. Inflorescences axillary. Flowers bisexual, regular, with distinct calyx and corolla; sepals 4 or 5; petals 4 or 5(–8), free; stamens >50, fused; anthers often with complex or simple glands. Fruit simple, slightly dehiscent or indehiscent, drupe or berry, fleshy; seeds 1–many, without wings.

CASUARINACEAE

Small to medium trees; bark rough; small branchlets (twigs) jointed; leaves small, scaly, arranged in whorls; flowers unisexual; male flowers in slender spikes; female flowers in globular head; fruit a cone.

CELASTRACEAE

Trees, shrubs or lianas (rarely herbs); leaves simple, usually opposite, usually with margin toothed; stipules small, caducous; petals free; fruit capsular; seeds with aril.

CHLORANTHACEAE

Trees, shrubs, and herbs; small branchlets with swollen nodes; stipules present; leaves opposite, simple, with margin entire or toothed; venation pinnate. Bracts present, minute, sepaline. Flowers usually reduced, bisexual or unisexual (then plant dioecious), zygomorphic, perianth absent or sepals 1–3. Stamens 1–5, free; filaments absent. Fruit simple, indehiscent, drupe, fleshy; seeds 1, without wings.

CHRYSOBALANACEAE

Trees and shrubs; stipules present. Leaves spiral, simple, with margin entire; venation pinnate. Flowers bisexual or unisexual (then plants monoecious), slightly irregular or asymmetric, with a hollow receptacle, with distinct calyx and corolla. Sepals 5. Petals absent, or 1–5, free; stamens (2–)5–20(–300); fruit simple, indehiscent, drupe non-fleshy, or slightly fleshy; seeds 1, without wings

CLUSIACEAE

Trees or shrubs; leaves opposite, with margin entire; plant dioecious; stamens with filaments as stout as anthers; style shorter than ovary. Garcinia is the only genus in this family.

COMBRETACEAE

Large trees, buttressed; outer bark mostly fissured; wood yellow; stipules absent; leaves usually simple, alternate, with margin entire; flowers bisexual or unisexual (then plant monoecious), regular, with distinct calyx