Using the Interactive Identification KeyThe identification key of the 'Guide to the trees of Papua New Guinea' is to assist people to identify the more common trees that grow in the Morobe Province of Papua New Guinea. It is not designed to identify trees from other provinces.
The features used to distinguish the trees included in this 'Guide' can be combined in any order to assist with the identification. However, it is important to only use features about which you are certain. It is important to remember that here are a several reasons why it will not always be possible to reduce the number of possible species down to one. Therefore, when trying to identify a tree by using this 'key', initially the aim should be to reduce the number of possible species to fewer than 10 or 15 possibilities. At this point, the descriptions and/or images should be compared with the tree being identified. It may be possible to identify the tree without further use of the 'key'. In particular, if there are only a few possible species that are comparable with the tree being identified, then it is unwise to continue adding additional features of doubtful applicability in the hope of reducing the number of possibilities to one.
This is a prototype version of an interactive information and identification system to the common trees of Papua New Guinea. To open the PNGtrees identification tool ('key') [CLICK here]. The following points should be considered when using the 'key':
- It must be remembered that this 'key' is only designed to be a guide to the identity of a plant.
- Although we have tried to minimise the technical terms used in this 'Guide' (for details refer to the 'Data Dictionary'), the definition of these, together with the non-technical terms, should be fully understood before using the 'key'. 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.
- A tree is defined as a single stemmed woody plant.
- The majority of 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. It is hoped that these additional examples may prove useful to students of the tree flora of the Morobe Province.
- When comparing leaf features of the tree with the descriptors used in the 'key', 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, flower and fruits features 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.
- If you know which family the tree belongs to then this information can be used to identify the species. Naturally, the use of family names requires some additional previous botanical knowledge. If you are unsure of the family to which the tree belongs, then do not use this feature. A tree that is incorrectly assigned to a particular family can not be correctly identified.
- Even if the tree has been fully identified by the use of 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, P.N.G. References on how to make botanical collections suitable for identification purposes include Foreman & Bridson (1989), Victor et al. (2004), and Womersley (1969).
- If after comparing the name of the tree, as suggested by the 'key', does not match the species description and/or authenticated herbarium material, then the 'key' has not provided the correct answer. The whole identification process should be completed while carefully checking the features selected. The possible reasons why the 'key' will not correctly identify the tree include: incorrect interpretation of the features by the user; the species description and features assigned to that species have been incorrectly or incompletely recorded by the authors; or this species has not been included in this first part of the 'Guide to the trees of Papua New Guinea'.
Morphological featuresThe morphological features used in this 'key' include the following:
General Features - habit, trunk features, bark and indumentum on branches;
Leaf Features - general leaf features, including leaf position, arrangement on branchlets, petiole, colour, indumentum; and more specific features, such as - lamina shape for simple leaves or compound leaflets, lamina colour, base, margin and apex features, venation, stipules;
General Flower Features - arrangement, presence of cones/strobili, sex of the flowers, size and symmetry of flowers; perianth features; staminal (stamens) features; and features of the gynoecium (including ovary, and style);
Fruit Features - arrangement, size, colour, surface, texture, structure, dehiscence mechanism and type;
Cone Features - presence, size and colour;
Seed features - number, size, shape, presence of wings.
Group Name featuresThe group name features include: group (whether the tree is a conifer or dicotyledon), family name, tradename and timber group names.